1. Many Christian churches confess, the Athanasian Creed on Trinity Sunday because it teaches the doctrine of the Trinity so clearly. The revealed and saving God is Triune, one God in three persons. This is clearly taught also in the OT. For example Is. 61:1. "In the name of the Father and of the Son and of the Holy Ghost" is the clearest statement of the Trinity in the Bible. The three ecumenical creeds are based on this phrase. "Name" means revelation and power. There are not three but only one. The Triune God is the saving God. The Father sent the Son, the Son became man and saved us, the Holy Spirit came on Pentecost to bring this message to all nations.
2. Jesus had appeared three times to His disciples after His resurrection, twice in Jerusalem (Jn. 20:19-29) and once at the Sea of Tiberias (Jn.21:1-23). Mt. 28:16-20 is the fourth recorded appearance. This passage is parallel to Mk. 16:15-18 and very likely also I Cor. 15:6. Shortly thereafter Jesus ascended into heaven at Bethany, east of Jerusalem. Lk. 24:50. There were only eleven because Judas had not been replaced.
3. Three times Jesus told the disciples to go to Galilee after His resurrection. Mt. 26:32; 28:7.10.
4. Vs. 17 says "when they saw Him". Very likely that means that He suddenly appeared to them as in His other appearances. From His conception in Mary's womb into all eternity the entire Godhead abides in Jesus. Before His suffering and death He did not always show the qualities of His divinity. But He proved it with His miracles and the transfiguration.Ever since He became alive in the tomb He uses His divine powers all the time. After His resurrection He appears and disappears but His divinity and humanity are everywhere. He said "Lo I am with you alway". He is with us also as a man.
5. Vs. 17 also says that "some doubted". They did not doubt His resurrection. Very likely His sudden appearance caused them to doubt. But when He spoke to them evidently they believed. It is a comfort to a sinner like me to hear that even some of Jesus' disciples doubted. But Jesus did not scold them. On Ascension Day (Acts 1:6) some of the disciples asked Him a foolish question about the kingdom. But He gently corrected their false thinking.
6. Jesus says: "All authority has been given TO ME". This must mean His human nature because His divine nature already had all things. Read Mt. 9:6 and 11:27 and Jn. 3:35. The Father has given all things into the hand of His Son's human nature. Therefore, Jesus, the God-man, has all authority over everything in heaven and on earth.
7. John the Baptist, his disciples and Jesus' disciples baptized people during Jesus' public ministry. But that was limited to Israel, the Jews. See Jn. 1:31. But Jesus' command to His disciples in Mt. 28 is for all nations, both Jews and Gentiles. Before and after, both baptisms forgave people their sins.
8. The church makes disciples of people by baptizing them and by teaching them. Sometimes they baptize before they teach, for example infants, and very often they teach before they baptize. Cf. the Book of Acts.
9. Teaching people to observe all that Jesus commanded means the whole Bible, Law and Gospel. Pastors must be good teachers for men, women and children. Nothing keeps people with the church as does good preaching and good teaching. Always prepare carefully. Don't be sloppy!
10. Baptism and teaching reveal the saving Trinity to the sinner. The Father adopts us as His children. Gal. 3:26-27. The Son becomes our Redeemer. Eph. 5:26; Gal. 3:27. The Holy Spirit becomes our Comforter. Eph. 1:14. He lives in us. I Cor. 3:10. The whole Trinity lives where there is faith in Christ. Jn. 17:21.
11. Vs. 17 says that the eleven worshipped Jesus. This is the first time that the Gospels mention them worshipping Jesus. Once and for all they truly realized that this Jesus was true God and the Savior of the world.
12. God comes to us only through the means of grace, Word and Sacraments.
THEME: In The Name Of The Father And Of The Son And Of The Holy Spirit
Our theme is a summary of an eternal truth. Both the OT and the NT teach the Trinity of God. God said: "Let US make man" Gen. 1:26. The word for God in Hebrew is ELOHIM which is plural not singular Ps. 110 begins with "The Lord said to my Lord." Is. 61 begins "The Spirit of the Lord is upon Me." Jesus quotes this of Himself at Lk. 4:18. The word "Me"' stands for Jesus. In the NT the Trinity is taught in many places. For example, Jn. 14:16; 14:26; 15:26; 16:7. The Triune God is the saving God. We begin our worship services in the name of the Triune God.
I. GOD REVEALS HIMSELF AS THREE IN ONE AND ONE IN THREE
A. There is only one God. The first commandment (Ex. 20:3) reads "You shall have no other gods before ME." There is only one God. "You have not listened to ME" God says at Jer. 25:7. At Gen. 17:1 God told Abraham: "I am Almighty God; walk before ME and be blameless." God told Moses (Ex. 3:14) "I am Who I am." God said at Deut. 6:4 "Hear, 0 Israel: the Lord our God, the Lord is One." St. Paul says at I Cor. 8:4 and 6: "There is no other God but ONE" and "There is only ONE God." Jesus says at Jn. 10:29 "I and My Father are ONE." There are not three gods but only One God, one in essence, from all eternity.
B. There are three persons in One God. I Cor. 8:6 reads "There is only one God, the Father, of whom are all things, and we for Him; and one Lord Jesus Christ, through whom are all things." The unity and Trinity are here mentioned side by side. When Jesus was baptized the Father spoke from heaven, the Son was being baptized and the Holy Spirit descended as a dove. Mt. 3:13-17. When Jesus ascended to heaven He prayed the Father to send the Spirit. Jn. 14:16; 14:26; 15:26; 16:7. All three creeds (Apostles, Nicene, Athanasian) ascribe creation to the Father, redemption to the Son and sanctification to the Holy Spirit, God is one in essence and three in persons. We cannot fathom that mystery but we believe it. All three articles of the creed are by faith only. We cannot fully understand but we believe what God says.
II. THE TRIUNE GOD AND THE GREAT COMMISSION
Everything necessary for our salvation has been done. Now our work is to bring this salvation to the whole world. We are to go to all nations.
A. The Almighty God stands behind us and goes with us. All power in heaven and on earth has been given to the God-man Jesus Christ. He is King of kings and Lord of lords. He will reign forever. The Father gave Christ's human nature all things. Mt. 11:27. Jn. 3:35 says "The Father loves the Son and has given all things in His hand. He who believes in the Son has life eternal." Jesus uses all power in heaven and earth to save sinners. The last vs. of our text assures us that Jesus stays with us 'til the end of the age. Father, mother, sister, brother may forsake us but Jesus will never forsake us. He is faithful to His promise.
B. The Revelation and the Power of the Triune God empower us and our work. "Name" in our text means "revelation and power". The Triune God has revealed Himself to us. The Triune God gives His means of grace power. We make disciples of people by doing two things: baptizing and teaching. That is the work of the church. Sometimes we baptize before we teach. Sometimes we teach before we baptize. But both baptism and the teaching have God's saving power in them. Baptism and teaching forgive people and give them faith for everlasting life. Preachers must take care to believe the Lord and do what the Lord says here. Is. 55 says that God's Word is like rain from heaven which will do as the Lord wills. Peter says that baptism saves us just as the waters of the flood saved Noah.
The church has only one work, to save sinners. God has given the church the power and the means to do this work.