Acts 1:8

⁸ But you will receive power when the Holy Spirit has come upon you, and you will be my witnesses in Jerusalem and in all Judea and Samaria, and to the end of the earth.”

Luke 24:47-48 

⁴⁷ and that repentance for the forgiveness of sins should be proclaimed in his name to all nations, beginning from Jerusalem. ⁴⁸ You are witnesses of these things.