Power to bear witness

“It is not for you to know times and dates that the Father has decided by his own authority, but you will receive power when the Holy Spirit comes on you, and then you will be my witnesses not only in Jerusalem but throughout the ends of the earth.” (Acts 1: 7-7)
“I have chosen you from the world to go and bear fruit that will last.” (John 15: 16, 19)
“I will bear a witness to you in the world, O Lord. I will spread the knowledge of your name among my brothers, alleluia!” (Psalm 17: 50:; 21: 23)