I’m thankful for your friendship with this individual; some Christians, I’m afraid, don’t want anything to do with people who are different from them. But God loves them—and so should we! The Bible says, “Be wise in the way you act toward outsiders; make the most of every opportunity” (Colossians 4:5).
Yes, it would make sense for your friend to stop and think about his escape from harm. And you’re right: God is the One who spared his life—and I believe He did this so your friend would have another opportunity to turn to Christ and discover the hope and peace He alone can give. The Bible says that God “is patient with you, not wanting anyone to perish, but everyone to come to repentance” (2 Peter 3:9).
The most important thing you can do is pray for your friend. Right now he has hardened his heart against God, and logic alone won’t change him (although you should be prepared to challenge his ideas if God gives you an opportunity). But God can change him, and you should pray that He will.
In addition, ask God to help you be an example to him of a life that has been changed by Jesus Christ. Does he see Christ’s love and joy and peace in you? Right now he wants to run his own life—but that is a dead-end road. Ask God to use you to show him there is another way—the way of Christ.