Matthew 28:20

Teaching them--This is teaching in the more usual sense of the term; or instructing the converted and baptized disciples. to observe all things whatsoever I have commanded you: and, lo, I--The "I" here is emphatic. It is enough that I am with you alway--"all the days"; that is, till making converts, baptizing, and building them up by Christian instruction, shall be no more. even unto the end of the world. Amen--This glorious Commission embraces two primary departments, the Missionary and the Pastoral, with two sublime and comprehensive Encouragements to undertake and go through with them. First, The MISSIONARY department (Mat 28:18): "Go, make disciples of all nations." In the corresponding passage of Mark (Mar 16:15) it is, "Go ye into all the world, and preach the Gospel to every creature." The only difference is, that in this passage the sphere, in its world-wide compass and its universality of objects, is more fully and definitely expressed; while in the former the great aim and certain result is delightfully expressed in the command to "make disciples of all nations." "Go, conquer the world for Me; carry the glad tidings into all lands and to every ear, and deem not this work at an end till all nations shall have embraced the Gospel and enrolled themselves My disciples." Now, Was all this meant to be done by the Eleven men nearest to Him of the multitude then crowding around the risen Redeemer? Impossible.

— Jamieson-Fausset-Brown Commentary (public domain)