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:
20 Teaching them to observe all things whatsoever I have commanded you: and, lo, I am with you always, even unto the end of the world. Amen.
Most Christians believe this command is given directly to us to fulfill. However, the original command that is called the great commission is a directive to follow all of Jesus' commands. In order to obey it, we would have to become proselytes and obey the modern Jewish Rabbis.
Obviously, this would contradict the gospel of Paul (see Galatians).
Having said that, all Christians are commanded to confess Jesus and give a witness to the world which fulfills the purpose of the so-called great commission.
That plain enough for you?