Acts 9:4-6

 "Then he fell to the ground, and heard a voice saying to him, 'Saul, Saul, why are you persecuting Me?'"

 "And he said, 'Who are You, Lord?' Then the Lord said, 'I am Jesus, Whom you are persecuting. It is hard for you to kick against the goads.'"

 "So he, trembling and astonished, said, 'Lord, what do You want me to do?' Then the Lord said to him, 'Arise and go into the city, and you will be told what you must do.'"

 (If God would redeem someone as awful as Saul, and turn him into one of the greatest missionaries of all history, then what do you think God is capable of doing with you?)