“The Late Show” host Stephen Colbert is known for wearing his Catholic faith on his sleeve, often weaving religion into his criticism of President Donald Trump or using it to call out immoral actions of fellow Christians.

But in a candid conversation on the talk show “Faith in Focus,” published Thursday, Colbert revealed that his religious convictions haven’t always been so strong.

He spoke about how he’d struggled with doubt in his younger years. He told the show’s host, the Rev. James Martin, a Jesuit priest and editor at large at the Catholic magazine America, that he was “convicted of my own atheism” in his early 20s.

“I had lost my faith in God, to my own great grief,” Colbert said. “I was sort of convinced that I had been wrong all this time, that I had been taught something that wasn’t true.”

But then, he said, there was a moment when all of that changed.

After graduating from Northwestern University in 1986, Colbert joined a comedy troupe in Chicago. At age 22, he said he was walking through the streets of Chicago on a cold night when a stranger handed him a little green pocket Bible that contained the Christian scriptures and the books of Psalms and Proverbs.

YouTube / America - The Jesuit Review Stephen Colbert speaks with the Rev. James Martin on the Catholic program "Faith in Focus."

Colbert remembered that the pages were frozen stiff, so he had to crack the book open. What appeared was an index listing verses to read based upon the emotions that a person might be feeling.

Colbert said he was feeling “anxious” at the time, so he flipped to the Bible verse recommended for those struggling with anxiety.

It turned out to be Jesus’ Sermon on the Mount, which contains the verse, “Therefore I tell you, do not worry about your life, what you will eat or drink; or about your body, what you will wear. Is not life more than food, and the body more than clothes? ... Can any one of you by worrying add a single hour to your life?”

The words seemed to speak directly to him.

“I was absolutely, immediately lightened,” Colbert recalled.

“I stood on the street corner in the cold and read the sermon,” he said. “And my life has never been the same.”

He told Martin he still tries to carry a copy of the Bible with him wherever he goes.

And when he prays and thinks about God now, Colbert said he thinks about love. He described his image of God in near-mystical terms.

“What I’m imagining is some triune opening, like a bay door ... opening up and through which I can go, and on the other side of that is freedom,” he said. “And that has to do with love and acceptance.”