What prompted Paul to change his life? Jesus called his name and asked him a question. That's what happened at our numerous conversion experiences.
Though God is cosmic, we've had experiences of God being personal with us. It's the whisper, a truth uttered softly, words that beg action. When God speaks to us, it's never a long soliloquy. Not condemnation. It's a life altering question posed. And, it is our truthful answer to Jesus' questions that produce new life. Help us to answer honestly Lord!
There's no magic in conversion. It's a lifelong partnership of saying yes to God. Our next conversion, a more full embrace of Jesus' truth, is already at work in us. Why? "...to equip the saints for the work of ministry, to build up the body of Christ and to grow up into the full stature of Christ." Ephesians 4. 12-13