Luk 24:47 (ASV) and that repentance and remission of sins should be preached in his name unto all the nations, beginning from Jerusalem. Thats pretty simple.
This one thing I do, forgetting those things which are behind, and reaching forth unto those things which are before, I press toward the mark for the prize of the high calling of God in Christ Jesus. Philippians 3:13-14 (KJV)
