So why was there a Great Commission? Why did Jesus instruct his Disciples to "Go ye therefore, and teach all nations, baptizing them in the name of the Father, and of the Son, and of the Holy Ghost: Mat 28:19"? Or did I take that of context to?

Why would Jesus tell his Disciples to go out to ALL nations if he was going to chose. Jesus didn't say Go ye therefore, and teach all nations that my father hath chosen, he said "Go ye therefore, and teach ALL nations."

Am I missing something here?