The Great Commission was delivered to New Testament Church members by Jesus Christ. Our mandate (Commission) is to make disciples throughout all nations, to baptize them in the name of the Father, Son, and Holy Spirit. In addition we are to teach them how to observe the whole counsel of God's Word, to live and follow His instruction.
Matthew 28:19-20
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.