"... Thus it is written, and thus it behoved Christ to suffer, and to rise from the dead the third day: And that repentance and remission of sins should be preached in his name among all nations ..." (Luke 24:46-47)
"Go ye therefore, and teach all nations, baptizing them in the name of the Father, and of the Son, and of the Holy Ghost: 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." (Matthew 28:19-20)
Elements Of The Commission:
The Great Commission first and foremost teaches salvation. Christ Jesus commissioned His church teach all people the necessity of repentance toward God, and faith toward Christ's bloody death on the cross in our stead (Luke 13:5; Acts 17:30; Romans 3:23-26, 5:8-10; Mark 1:15; Acts 20:21).
The second part of the Great Commission is water baptism as a token of one's repentance of sins and a symbolic picture of one's faith in the death burial and resurrection of Jesus Christ for salvation, and as the method of receiving members into the church (Matthew 3:5-11; Acts 2:41).
The third part of the Great Commission has to do with "teaching" saved and baptized folks to "observe" all things that God commanded in His Word. The word "observe" in Matthew 28:20 primarily has to do with caring for the words of the text of the Bible and secondly do what it says. In English "observe" means to be aware of, especially through careful and directed attention, make a systematic observation of, watch attentively. (American Heritage Dictionary) "Observe" in this verse comes from the Greek word "tayreho" (Strong's Dictionary #5083) means to guard from loss by keeping the eye upon. Figuratively it means to hold fast, keep, watch. By implication it means to maintain in custody. In Matthew 23:3 it say, "All therefore whatsoever they bid you observe, that observe and do ..." Here we see that there is a difference between observing and doing. This is an oft overlooked part of the Great Commission is to teach the church to guard the words of God from loss. By omitting this portion of the Great Commission there is no way to "... behave thyself in the house of God, which is the church of the living God, the pillar and ground of the Truth." (1 Timothy 3:15; cf. Jude 3; Acts 20:27-30) In past centuries attention this part of the Commission always brought Baptists back in line with Truth when in failure or error (John 16:13, 17:17), but the many of Baptists today are overlooking this important command completely. To many have fallen for corrupted and polluted versions of the Scriptures. The Bible cannot be fully taught and followed if it is not pure.
Going by Proxy:
The Lord commanded the church saying:
"... Go ye into all the world, and preach the gospel ...." (Mark 16:15)
"Go ye therefore, and teach all nations ..." (Matthew 28:19)
"... ye shall be witnesses unto me both [locally and everywhere else] ... unto the uttermost part of the earth." (Acts 1:8)
There is only one way for the church to obey this command. That is by proxy, by sending out messengers to act on behalf of the local churches.