Bono writes of his dad:

"The spiritual journey was interesting to him. Because he wasn't a believer; he didn't believe in God towards the end. He was a Catholic, but he lost his faith along the way... I think the Church wore him down, all the scandals, and all that stuff. I would give him a Bible, or I would offer up, if he was interested, any kind of insights I might have had to some of the Gospels, or the way they were written, or the context of a particular passage. But finally he didn't buy into it. Yet he seemed to think this was the most important thing I had to offer. In fact, it was what he liked best about U2: our faith.

Occasionally, he would ask about my belief in God: "There's one thing I envy of you.  I don't envy anything else," he said to me one time... "You do seem to have a relationship with God." And I said: "Didn't you ever have one?" He said: "No." And I said: "But you have been a Catholic for most of your life." - "Yeah, lots of people are Catholic. It was a one-way conversation... You seem to hear something back from the silence!" I said: "That's true, I do." And he said: "How do you feel it?" I said: "I hear it in some sort of instinctive way, I feel a response to a prayer, or I feel led in a direction. Or if I'm studying the Scriptures, they become alive in an odd way, and they make sense to the moment I'm in, they're no longer a historical document." He was mind-blown by this."