Luke 24:47-49

and that repentance [necessary] for forgiveness of sins would be preached in His name to all the nations, beginning from Jerusalem. You are witnesses of these things. Listen carefully: I am sending the Promise of My Father [the Holy Spirit]upon you; but you are to remain in the city [of Jerusalem] until you are clothed (fully equipped) with power from on high.” [John 14:26; Acts 1:4]