(Kersten, The Heidelberg Catechism in 52 Sermons, Vol.2, Part 11)

Swearing An Oath Religiously

Lord's Day 37

Psalter No. 389 st. 1, 6
Read Isaiah 54
Psalter No. 243 st. 6-9
Psalter No. 428 st. 8
Psalter No. 24 st. 1, 2


    God cannot lie. He is not a man that He should lie; neither the son
of man, that He should repent. Nevertheless, He has not only given us
His Word, but also the confirmation of that Word with an oath, so that
the power of unbelief might be broken in His people, and the strength
of their souls be in Him, Who will surely confirm His Word. To that end
He gave man His covenant, namely the covenant of works, while in the
state of rectitude. It was the covenant of works, because in that state
man had the ability to obtain life incorruptible and eternal, by
working in his own strength. When that covenant was broken by wilful
disobedience, the Lord revealed the covenant of grace. There are (it is
by repetition I say it again) two covenants concerning man's eternal
state: the covenant of works and the covenant of grace. In the covenant
of grace Christ has become the Surety for the debt of His elect in
eternity. In that covenant, all are included of whom Christ said,
"Father, Thine they were and Thou gavest them Me." Here in time God
incorporates them into the covenant of grace, so that they may be freed
from the curse under which they lay because of their relationship to
Adam, their covenant head, and attain life eternal by this
incorporation into the covenant, that is, by regeneration. Indeed, the
Lord confirms that covenant with His people so assuredly, that it will
never be broken. He not only called it a covenant of salt, of
redemption, and of peace, but He even says, "For this is as the waters
of Noah unto Me; for as I have sworn that the waters of Noah should no
more go over the earth; so I have sworn that I should not be wrath with
thee, nor rebuke thee." Because God has sworn to Noah in a covenant, He
upholds the whole world in a covenantal manner. He does so by His
general Divine providence. He does not do so by virtue of the merits of
Christ, for providence is the work of the Father. Thus the Lord
established the covenant with Noah, of which the rainbow is a sign. Now
the Lord says, "As I have sworn to Noah that the waters should no more
go over the earth, so have I sworn that I should not be wrath with
them, nor rebuke them, that the peace of the covenant of grace and the
salvation in Christ shall be theirs, and that they shall never lose
their interest in that covenant, because they are chosen in Christ." He
is the Head of the church, the last Adam. In this covenant then, as in
other instances, it has pleased the Lord to oblige Himself to His
people by an oath. In another place He testifies, "I have sworn by
Myself, the word is gone out of My mouth." Thus the Lord wishes to
strengthen His people by this oath and encourage them, so that by faith
they shall trust in God Whose word shall certainly be confirmed. If God
then swears an oath, if He swears by Himself because there is none
greater than He by whom He can swear, then He also testifies that it is
permissible to swear. He also gives us the oath so that when such an
oath is demanded of us, we may attest to the truth by calling on that
God Who is eternal and true, Who knows our hearts and tries our reins.
This is to swear religiously. Let us then give our attention to it at
this time, according to the explanation given in the thirty-seventh
Lord's Day of our Heidelberg Catechism.
    Lord's Day 37
101. May we then swear religiously by the name of God?

A. Yes; either when the magistrates demand it of the subjects, or when
    necessity requires us thereby to confirm fidelity and truth to the
    glory of God, and the safety of our neighbor; for such an oath is
    founded on God's Word, and therefore was justly used by the
    saints, both in the Old and New Testament.

Q. 102. May we also swear by saints or any other creatures?

A. No; for a lawful oath is calling upon God, as the only one who knows
    the heart, that he will bear witness to the truth, and punish me
    if I swear falsely, which honour is due to no creature.

    We are shown here:
      I. the lawfulness of the oath;
     II. the rules governing the oath;
    III. the subject of the oath.
    In our Catechism two Lord's Days are used for the third
commandment. It merits our attention. When you compare this to the
treatment of the other commandments, the question arises: Why are two
Lord's Days used for the third commandment? It is an indication of how
zealous the composers of the Catechism were for the honour of God's
Name. There is no sin greater, or more provoking to God, as we heard
the previous time, than the profaning of God's Name. Cursing or
blaspheming the Name of God is in reality reproaching God and violating
His honour. Moreover, in the conflict with Rome in which our fathers
were engaged, they were confronted with the dreadful evil of Rome's
universal abuse of God's Name and her minimizing the sinful swearing of
an oath. Therefore the Catechism devotes two Lord's Days to the
hallowing of God's Name. One Lord's Day deals specifically with
cursing, followed by a separate discussion of the oath.
    You are tempted to say, "Oh, that Rome only were guilty and the
Protestants not guilty of this great sin!" But how this evil of using
God's Name in vain, and of cursing and swearing permeates all classes
of our people, both on land and on sea! How necessary it is when
discussing the Catechism every year, to remind one another earnestly
that there is no sin greater than the profaning of God's Name, in order
that a curse shall never come upon our lips. Furthermore, our fathers
were not only confronted with Rome, but also with the Anabaptists. They
were really the Socialists of the sixteenth and early seventeenth
centuries. For that reason the government interfered with them. They
refused to submit to any authority, saying, "A Christian may not accept
a government office; a Christian may not carry a sword, nor wage war."
(When we discuss the sixth commandment concerning killing we shall
return to this.) A Christian was also forbidden to swear an oath.
    The government had to oppose those rebellious people in order to
suppress a revolution. The church of God also entered the conflict.
What caused the Anabaptists to arrive at such opinions? Their aim was
to place the church, God's people, outside of the world, and draw the
kingdom of God, which will be perfect only in heaven, down to the
earth. They wanted to place the entire realm of the Christian life
outside of the world. Their fundamental error lay in their wrong
conception of the birth of the Lord Christ. The Son of God assumed our
human nature from the virgin Mary. We say that He assumed the human
nature in such a way that He is her own flesh and blood. He was
conceived in Mary's womb, borne under her heart until her days were
fulfilled that she should be delivered. According to the flesh He is
Mary's own flesh and blood, from the seed of Abraham. The Anabaptists
said, "No, He passed through Mary as water through a pipe." What
communion has the water with the pipe? What communion would the human
nature of Christ have with us if that were so? In that case the Lord
Jesus would stand outside of the human race. How then could He be our
Surety and Savior? Therefore the church took a strong stand against the
God-dishonoring position of the Anabaptists. That which the Anabaptists
held in regard to the incarnation of Christ, they also maintained in
relation to those whom they called Christians. According to them a
Christian stands outside of the world. He may not concern himself with
the entire world. Christians are drawn out of this present evil world.
The question is, what does the Scripture teach? Scripture does teach
that God draws His people out of the world spiritually, but that they,
although not of the world, yet are in the world, and that God's people
have a calling in this world. They shall be as a light in a crooked and
perverse generation. The Lord Jesus calls them the salt of the earth
and the light of the world. A light certainly is not placed under a
bushel. The people of God have no hidden life in the world but,
"Whosoever shall confess Me before men, him will I also confess before
My Father which is in heaven. Let your light so shine before men, that
they may see your good works, and glorify your Father which is in
heaven." The salt must not lose its savor, else it is good for nothing.
    Is this not diametrically opposed to the doctrine of the
Anabaptists? What the Anabaptists taught concerning the government also
conflicts with the Word of God. When the soldiers came to John the
Baptists, He did not say that they should break with the military, but
He showed them their duty. "You may not swear an oath", says the
Anabaptists, "for is a Christian not truthful? A Christian is born of
the truth, and therefore does not lie. Is it not written in Matthew 5,
'Swear not at all'? The Apostle James says the same thing in the fifth
chapter of his epistle." The Anabaptists appeal to these texts.
    Are these texts written in exactly these words? Yes, they are so
written. But there is one thing we must never forget. We may never take
spoken or written words out of their context, for then they receive an
entirely different meaning. If this is true among men, how much worse
it is when we lift God's Word out of its context and give it a meaning
that was not intended. What then is the meaning of the words quoted
from Matthew and James when viewed in their context? That we shall not
swear lightly. The Jews in Christ's days swore at random. They swore by
common things: by the temple, by the hair of their head, by heaven.
Therefore the Lord said, "Let your communication be Yea, yea; Nay,
nay." You may not swear by the temple, or by heaven, or by yourself;
such oaths are condemned. We shall learn more of this soon. We are
speaking now not about swearing lightly, but about swearing an oath
religiously. In ordinary life therefore, let your yea be yea and your
nay, nay.
    A Christian is indeed truthful, for he is born of the truth; but
all manner of sins cleave to him. Take your Bible when you come home
and read what it tells about the Bible-saints. Bible-saints did you
say? Yes, for they are sanctified in the blood and by the spirit of
Christ. But Abraham lied, saying, "Sarah is my sister;" and think of
that terrible case of Peter in the hall of Caiaphas. He began to
confirm with an oath that he had no part or lot with that Man. Yet
Peter was one of the true disciples of the Lord.
    Do not these two examples upset the Anabaptist's theory? Is it not
necessary to place God's people under a deep impression of an
All-knowing God, when they are about to swear an oath religiously by
the Name of God? The Catechism asks, "May we then swear religiously by
the Name of God?" and the answer is: "Yes." We may swear an oath by the
name of God, for God Himself has instituted the oath. To swear an oath
religiously is to call upon the holy Name of God, as upon Him Who alone
knows the heart perfectly and shall bear witness to the truth.
    What is included in such an oath? The honour of the omniscient God
above all creatures. No other person knows our thoughts. You can easily
say, "I did not mean it that way", for no one can look into your heart.
God only knows the inmost thoughts of the mind, even better than we
ourselves. When in swearing an oath we call upon the omniscient God, we
acknowledge Him Who knows all things and searches the heart. Swearing
is acknowledging God's omnipotence and righteousness. It is submitting
to divine punishment if I swear falsely. The Lord will compass me about
with His loving kindnesses if I call upon His Name in truth. May we
swear religiously in such a manner that the honour of God is exalted?
Yes. In this way God is acknowledged as God.
    Contrary to the erring Anabaptists, who wrest Scripture to their
own destruction, we agree with our Catechism that we may swear an oath
religiously by the Name of God. The Lord Himself commanded it in
Deuteronomy 6. He commanded by the mouth of Moses that the people of
Israel should swear by His Name, and swearing an oath was commonly
done. Abimelech swore; Jacob swore; David and Jonathan made a covenant
and confirmed it with an oath; Paul swore an oath. We have enough
examples in Old and New Testament to show that the oath was used by the
saints. Hence we may swear religiously by the Name of God.
    In fact we have full freedom to do so when called upon, so that we
may give God the honour of being the Omniscient One. However, as I now
come to my second point, this does not mean that we may swear
thoughtlessly. Rules have been established.
    The Catechism states those rules, saying: "Either when the
magistrates demand it of the subjects; or when necessity requires us
thereby to confirm fidelity and truth."
    David swore an oath rashly in I Samuel 25; swearing that there
would be nothing left to Nabal by morning. Herod swore rashly and it
cost the head of John the Baptist.
    Such rash oaths are improper. May the Lord keep us from them. But
the oath is lawful when the magistrates require it of us, because the
magistrates have the right to require such an oath. They stand in the
place of God and are called to administer judgment on earth in the name
of the Lord. Those magistrates oblige us to swear an oath. Is it not
alarming that many will not swear an oath because of atheistic and
anabaptistic reasons? Is it not even worse that the magistrates humor
such objections, saying, "If you do not wish to make an oath, just say,
'I promise'."
    It is improper for a subject to refuse to swear an oath. The
magistrate requires of the subjects in the presence of God that they
swear religiously in the Name of God to confirm fidelity and truth.
    This is also true when necessity requires it. For instance, if in
time of great need we are severely slandered, we may ask permission to
use the oath in the presence of God to verify the truth. Soldiers are
required to swear that they will be faithful to the government and the
people. Members of the Legislature must swear an oath of fidelity and
    There is also the ecclesiastical oath. You are asked to give your
word of promise when you make confession of faith. We must not think
that this confession is the same as the Roman Catholic confirmation.
Our fathers always warned us not to think so. We must banish the Romish
leaven from our worship services. One matter should penetrate deeply
into our hearts: When we stand before the pulpit to give our word of
promise before the congregation, we are subscribing ourselves with an
oath before God, to His Word and to the church. Not all of us were
converted when we made confession of faith, but he who makes confession
must remember that he is subscribing himself before God to His service
and His church.
    The ecclesiastical oath is apparent also at baptism when parents
answer "Yes" to the questions asked them. We have no time to go more
deeply into all these matters now, but think how often you have stood
there with your children and made your promise before the Lord.
Afterward, what did you do about the instruction of your children,
especially in these serious and perilous times, with a future in
prospect so dark that we fear and tremble when we raise our eyes to see
the tumult of the nations?
    The ecclesiastical oath is also taken, though silently before God's
omniscient eye, by those who partake of the Lord's supper. By faith
they bind themselves with an oath to Christ, testifying that they seek
and embrace salvation in Him.
    An ecclesiastical oath is also sworn when God's servants are
ordained in their office. Has it ever occurred to you what a heavy
burden rests upon our shoulders as God's servants, what a holy
responsibility we bear for all of you because we stood and gave our
word in that solemn promise, "Yes, with all my heart." When we then
admonish old and young from this place, seeing the congregation is
bound upon our hearts, do not think we are exceeding our bounds, for
God demands it of us. What cause for constant humiliation should that
oath be for God's servants, and for the elders too, who gave their word
of promise. When they come for family visitation, they must do more
than merely learn whether you attend church and Catechism classes
faithfully. (Parents, see to it that your children are also present,
that they do not quietly absent themselves when the elders come.) They
also must be visited. The elders must inquire about the conduct of your
children. That is not all. The elders must ask about your immortal
soul; they must ask about your inner life. They must show you that if
you are still unconverted, you can expect nothing but the eternal wrath
of God. They do not come to relate their conversion, but to instruct
you concerning eternal things. This they promised to do. Woe to persons
who refuse to receive them. Let these take heed.
    Furthermore there is also the oath made by the deacons concerning
their care for the poor. What a joy and comfort it is for a pastor when
the deacons do their work conscientiously. God demands it of them.
    Now a few words are in order about the spiritual oath of which we
find an example in Isaiah 19, "Five cities in the land of Egypt shall
swear to the Lord of hosts." That means that they shall dedicate
themselves totally to the service of the God of Israel. Let us and our
children dedicate ourselves also to God and His service. Let our
children, when they are still young become acquainted with the old
truths. The tried doctrine can endure diligent search. I dare challenge
the whole world boldly, because the Word of God endures forever and
shall never be moved. What our Reformed fathers taught is also worthy
of investigation. In their writings we are taught something else than
the insipid doctrine of the three covenants with its damaging
consequences for the church. Otherwise I would not warn against it so
seriously. Read and study and make an effort to become acquainted with
the truth. Then you will see that ours will be the victory. Our fathers
never taught the things that are presented to us in these days. Let us
swear a spiritual oath to God and commit ourselves to the truth. As a
means in the hand of the Holy Spirit, this could bring us to another
choice, the spiritual choice that Ruth made. She gave up all of Moab
and chose the side of a poor widow. What a wonder it would be if God's
grace were glorified in like manner today in poor sinners. Even though
the whole world would then mock us, we would say, "In spite of all, I
still cleave to the poor people of God. With them I choose to live and
to die." Then we have pleasure in the service of God, and with a total
surrender of heart, we dedicate ourselves to His service and seek all
our salvation in the revealed Word of God. Yes, those people are always
obliged to renew their choice and repeat their spiritual oath before
    Is that oath permitted? Yes, but rules were given to govern it and
swearing of the oath was done in various ways. In Genesis 15 we read of
the establishment of the covenant between God and Abraham. There God
Himself passed between the two halves of the sacrifice. That
represented the covenant made by oath and the one who broke the
covenant deserved to be cut in pieces. Abraham took an oath from
Eliezer when he was sent out to find a wife for Isaac. Eliezer put his
hand under Abraham's thigh. The English often kiss the Bible. We raise
our right hand saying, "So help me God."
    Thus there are various ways of swearing an oath. But it is most
important to realize what the oath is. It is calling upon God Who will
not only bear witness to the truth if we swear truly, but will
certainly punish us if we swear falsely.
    God alone is the object of the oath, because He alone is
omniscient. With this we commence a brief discussion of our third main
    By Whom must we swear such an oath? Only by the Name of God. Not by
the saints? Not by saint Mary or saint Peter or some other? No,
certainly not! Nor by the angels. That is as clear as can be. Not by
the saints, because their souls are in heaven, praising God perfectly
day and night. They do not know our hearts and know nothing of us.
Abraham is ignorant of us and Israel acknowledges us not. There is but
One Who knows our hearts. We are not to swear by Angels because they
are only ministering spirits, sent forth to minister for them who shall
be heirs of salvation. There is but One Who knows our hearts and tries
our reins. He is the true and eternal God. If men swear by the saints,
or by the angels, or by any other creature, they are robbing God of His
crown. This is the abomination of Rome. Rome dishonors the saints and
dishonors God, by Whose Name alone we shall swear religiously. The Lord
Jesus swore an oath in the Name of His Father, when He stood before
Caiaphas and the ecclesiastical authorities. The angel in the
Revelations to John swore by Him that liveth forever and ever, that
there should be time no longer. Thus God alone will receive the honour.
By swearing an oath religiously by the Name of God, God is acknowledged
as God, the only object of our oath, according to the rules which are
prescribed when the magistrates demand it or when necessity requires
it. Under such circumstances the oath will be sworn with full liberty,
and it will reflect something of that dedication of ourselves to the
Lord, of which David sings in Psalter No. 428: 8.
        "Thy Word is as a lamp unto my feet,
        A light upon my pathway unto heaven;
        I've sworn an oath, which gladly I repeat,
        That I shall keep, as always I have striven,
        Thy righteous judgments, holy and complete,
        When unto me Thy helping grace is given."
    Young and old, let it be a rule of life for us that our yes be yes
and our no, no. We need not confirm the truth of our words with strong
words, such as, "As truly as I stand here" or with such other unseemly
expressions, as are often used. Above all, let us use the Name of God
with fear. When we say yes, let it be yes and that is all; and if we
say no, let it be no, which should be enough among ourselves. They are
liars who need strong words. Let us realize in our daily lives that God
sees and hears everything. If, however, the authorities call us, or we
are in dire circumstances, we need not be afraid to swear a holy oath.
Some of God's children have asked, "May I do so?" Yes, you may with
full liberty! For you can say, "There is a God in heaven Whom I honour,
Who knows my heart and Who knows what is true and what is a lie. I can
freely say before the Lord that my words are true." Herein lies the
glory of God. Therefore God's people may, yea must swear religiously by
the Name of God.
    On the other hand, it is dishonoring to God if you say, "I refuse
to swear an oath. I shall say only: "I promise." In other words, let
swearing religiously by the Name of God be the rule of our life.
    Again, we have made an oath before God when we made confession of
faith. We made an oath before God when we stood and gave answer at the
baptism of our children. Does it ever occur to you, young men and young
women, that you were dedicated to God and His service by your parents
when you were baptized, and that you dedicated yourselves when you made
confession of faith? This does not mean that all of you became
regenerated persons. I have never taught you so. But I have a question
for you to consider and to take home with you: Do you ever think about
the truth? Do you ever think about what has been preached? Do you
search God's Word? Do you ever read a Catechism sermon by one of the
old writers? Read Rev. Vender Kemp, who explains many precious truths.
Modern writings draw you away from the truth. Remember that you have
given your word of promise. God's church is built upon the pure
doctrine. Do we have the pure doctrine, delivered to us by the fathers?
If I should ever deviate from it, you are obliged to admonish me. I
hope, however, that the Lord will keep me from ever departing one step
from it. You must search the scriptures. Become familiar with the
Catechism. It should not be necessary for the ministers or elders to
help you recite your lessons in Catechism classes. Your fathers and
mothers should do that at home. The office-bearers cannot bring the
truth into the heart; that is God's work. But you should be more
diligent. Find out for yourselves. The more you study the truth, the
more pleasure you will find in it. Remember especially that God will
some day confront you with your oath. At baptism, we parents promised
to bring up our children in the fear of God. What have you done with
your oath? With me you will have to say, "How much we come short in the
nurture of our children." Then add to this that by our confession we
are members of the church. Through His Word the Lord works in our soul.
By nature we are in a broken covenant of works and in it we are subject
to eternal condemnation. But by regeneration we enter into the covenant
of grace.
    Without regeneration we are dead branches. What impression has this
truth made upon us? Soon the moment will come when the Lord will say,
"Why have you not sworn by the Name of the Lord in uprightness of heart
as the five cities of Egypt have done? Why have you not given heart and
hand to Me?" Surely the fault lies with us if we have not done so. On
the other hand, it is free grace only if God regenerates a sinner.
Sinners become the people of God when God glorifies His grace. Then
another choice is made in which they give heart and hand to the Lord.
They give up the whole world, even though it becomes necessary to beg
their bread. So much do they envy the happiness of God's people. In
this the hypocrite always falls short. He can repeat what he hears, but
he is never loosed from all that belongs to the world and to sin. This
is the portion of the upright. They may have much opposition, but they
still say, "In his service I delight." They are in the world, but not
of the world. They let their light shine, the light which God has given
in their hearts by His Holy Spirit. This is not imagination. Alas,
there is so much in the way of religious experience in which God has no
part. This is often the result of becoming religious without Christ.
When it is right in the heart, God's children swear an oath to God in
Christ, because salvation and the glorification of all God's attributes
lie only in Him. Now they wish to be saved only in the way in which
God's righteousness is exalted. This becomes the foundation of their
spiritual life. Afterwards, in the way of sanctification, they
experience that they come short in all things. The will thus renewed,
becomes itself active. Their shortcomings make them guilty before God
and cause them to feel their need of the power of the King. Do you know
what accompanies this at times? God's dear people become inwardly
detached from all things, because of the strong inward desire to some
day praise God perfectly and forever. At times I have a fervent longing
soon to praise God perfectly. It will not be long. Also for the entire
church it will not be long. Here we must pass through a world that lies
in wickedness, but soon God will take us up in glory. How remarkable is
that inward bond with God, to serve and fear Him! With it comes that
painful experience that when I would do good, evil is present with me.
But some day that will cease, and those poor people who have fought the
hard battle will receive the crown of which the world could not rob
them. David has pitifully complained, "They have made a public
rebellion, to remove the crown from my head." That crown is
incorruptible and fadeth not away. The day of salvation is coming. Then
we shall be before God's throne with body and soul. May the Lord grant
in our hearts those strong workings of His Holy Spirit to continually
swear by His Name, to hallow Him and to dedicate ourselves to His
service for the glorification of free grace in us according to His
eternal good pleasure. Amen. 

Kersten, Heidelberg Catechism in 52 Sermons, Vol.2
(continued in part 12...)

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