Acts 7:57b-59 The whole crowd rushed at Stephen, converged on him, dragged him out of the city, and stoned him. They laid their coats at the feet of a young man named Saul, while they were pelting Stephen with rocks. Stephen (as rocks fell upon him): Lord Jesus, receive my spirit.
God uses some of the unlikeliest people for His purposes and glory. It’s hard to believe that the Apostle Paul (originally a devout Jew named Saul) was responsible for persecuting so many pioneers of the Christian faith. The revered man who wrote key books of the New Testament was a vicious murderer!
Saul (Paul) wasn't satisfied with a little blood, he wanted lots of blood:
Acts 8 1-2 Some devout men buried Stephen and mourned his passing with loud cries of grief. But Saul, this young man who seemed to be supervising the whole violent event, was pleased by Stephen’s death. That very day, the whole church in Jerusalem began experiencing severe persecution. All of the followers of Jesus—except for the emissaries[a] themselves—fled to the countryside of Judea and Samaria. 3 Young Saul went on a rampage—hunting the church, house after house, dragging both men and women to prison.
Whatever you've done, whatever you've been, whatever you didn't do – God is ready and waiting for you. He transformed the murderous, hateful and vengeful Paul into the person who pretty much single-handedly influenced the church we know today.
God can do the same for you.
He made you in His image (Gen 1:26), which is a good reason to respect yourself, give up your sin-filled life and ask Him to give you the ultimate makeover.
He can do it, but you just have to ask.