Greek: 19 πορευθέντες μαθητεύσατε πάντα τὰ ἔθνη, βαπτίζοντες αὐτοὺς εἰς τὸ ὄνομα τοῦ πατρὸς καὶ τοῦ υἱοῦ καὶ τοῦ ἁγίου πνεύματος, 20 διδάσκοντες αὐτοὺς τηρεῖν πάντα ὅσα ἐνετειλάμην ὑμῖν. καὶ ἰδοὺ ἐγὼ μεθ’ ὑμῶν εἰμι πάσας τὰς ἡμέρας ἕως τῆς συντελείας τοῦ αἰῶνος.
My Translation: 19 Marching y'all must instruct all peoples, baptizing them in the name of the father and the son and the holy spirit, 20 teaching them to preserve everything that I've charged to you. And y'all must see me with y'all, every day until the end of the Eon [some manuscripts add: "Amen"].
KJV: 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.
My translations are purposefully stretched and should not be viewed as more accurate than the KJV translation unless I say so in the post. I'm trying to show the range lying between the original Greek text and the English.
I have not yet begun work on a post to discuss this Scripture Mastery selection, but I've posted up my translation until I finish the post.