Matthew 28:16 Then the eleven disciples went away into Galilee, into a mountain where Jesus had appointed them.
28:17 And when they saw him, they worshipped him: but some doubted.
28:18 And Jesus came and spake unto them, saying, All power is given unto me in heaven and in earth.
28:19 Go ye therefore, and teach all nations, baptizing them in the name of the Father, and of the Son, and of the Holy Ghost:
28:20 Teaching them to observe all things whatsoever I have commanded you: and, lo, I am with you alway, even unto the end of the world. Amen.
Jesus was commanding the eleven disciples. Jesus commanded them to teach all the nations to obey his commandments. This was preparation for the coming Davidic kingdom on earth. Israel was to be a light to the Gentile nations in the kingdom.They were commanded to baptize in the name of the Father, and the Son, and the Holy Ghost, where as before it was in the name of Jesus only because the Holy Ghost was not fallen on them. Isaiah 42:6 Isaiah 2:2-3 Acts 2:38 Acts 8:16
Mark 16:14 Afterward he appeared unto the eleven as they sat at meat, and upbraided them with their unbelief and hardness of heart, because they believed not them which had seen him after he was risen.
16:15 And he said unto them, Go ye into all the world, and preach the gospel to every creature.
The eleven disciples, were once again, the only ones who were given this commandment. They were to go and preach the gospel of the kingdom. The gospel of the coming kingdom on earth, in which Christ will reign along with the disciples. They were not preaching Paul's gospel. Matthew 24:14
16:16 He that believeth and is baptized shall be saved; but he that believeth not shall be damned.
The gospel of the kingdom required baptism. The salvation spoken of here is a physical salvation that would deliver Israel from the tribulation and the Antichrist. This salvation is Israel being saved to enter the kingdom on earth.
16:17 And these signs shall follow them that believe; In my name shall they cast out devils; they shall speak with new tongues;
16:18 They shall take up serpents; and if they drink any deadly thing, it shall not hurt them; they shall lay hands on the sick, and they shall recover.
These were signs that would only follow the disciples at the time the gospel of the kingdom was being preached. This gospel is not being preached today, nor does the church, the body of Christ have any basis to warrant any expectation that these signs have any application today.
16:19 So then after the Lord had spoken unto them, he was received up into heaven, and sat on the right hand of God.
16:20 And they went forth, and preached every where, the Lord working with them, and confirming the word with signs following. Amen.
The signs that would follow belief were only to confirm the authenticity of the word spoken of the coming kingdom.
Luke 24:46 And said unto them, Thus it is written, and thus it behoved Christ to suffer, and to rise from the dead the third day:
24:47 And that repentance and remission of sins should be preached in his name among all nations, beginning at Jerusalem.
The nations are Gentiles. Starting first at Jerusalem, the gospel of the kingdom would be preached. It is to the Jew first. Acts 15:7 Romans 1:16
The nations were to be given the same gospel of the kingdom the Apostles preached to Israel. Mark 13:10 Luke 9:6
The nations, as did Israel, were to repent and believe on the name of Jesus for remission of sins. This is the same remission of sins that John and Peter preached. Mark 1:4 Acts 2:38 Acts 10:43
24:48 And ye are witnesses of these things.
John and the eleven remaining disciples were witnesses. The church, the body of Christ can not be witnesses. Paul only was witness. John 1:7 John 15:27 Acts 1:22 Acts 22:15
24:49 And, behold, I send the promise of my Father upon you: but tarry ye in the city of Jerusalem, until ye be endued with power from on high.
The disciples were to remain in Jerusalem and wait for the Holy Ghost. This was fulfilled at Pentecost. Acts 2:1
John 20:21 Then said Jesus to them again, Peace be unto you: as my Father hath sent me, even so send I you.
20:22 And when he had said this, he breathed on them, and saith unto them, Receive ye the Holy Ghost:
20:23 Whose soever sins ye remit, they are remitted unto them; and whose soever sins ye retain, they are retained.
Jesus gave the authority to remit sins. The body of Christ has no such authority.
The commissions were given to the disciples only. They were to go unto the nations, the Gentiles. The body of Christ are to go to all men, to exhort that all be reconciled to God, through The Lord Jesus Christ. The body of Christ, the church, in this dispensation, are ambasadors of Christ to all. 2 Corinthians 5:20 Colossians 1:18