The 70-year-old Welcome to My Nightmare rocker decided it was time to change his rock-star lifestyle nearly 40 years ago, when he found himself throwing up blood.
Speaking to the New York Daily News' Confidential, he explained: "Everything that could go wrong was shutting down inside of me. I was drinking with Jim Morrison and Jimi Hendrix and trying to keep up with Keith Moon and they all died at 27."
The wake-up call led to Cooper - who is preparing to reprise his role as King Herod in NBC's live version of Jesus Christ Superstar - rededicating his life to Jesus.
"My wife and I are both Christian. My father was a pastor, my grandfather was an evangelist. I grew up in the church, went as far away as I could from it - almost died - and then came back to the church."
While he acknowledged people may struggle to understand how he can be a rock musician but still be a Christian, he said it was entirely possible to be both.
"There's nothing in Christianity that says I can't be a rock star," he said.
"People have a very warped view of Christianity. They think it's all very precise and we never do wrong and we're praying all day and we're right wing.
"It has nothing to do with that. It has to do with a one-on-one relationship with Jesus Christ."
The 'School's Out' hitmaker said he reads the Bible daily, goes to church every Sunday, and is proud that none of his children have ever had problems with drugs or alcohol.
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