Gates was interviewed November 1995 on PBS by David Frost. Below is the transcript with minor edits.
Frost: Do you believe in the Sermon on the Mount?
Gates: I don't. I'm not somebody who goes to church on a regular basis. The specific elements of Christianity are not something I'm a huge believer in. There's a lot of merit in the moral aspects of religion. I think it can have a very very positive impact.
Frost: I sometimes say to people, do you believe there is a god, or do you know there is a god? And, you'd say you don't know?
Gates: In terms of doing things I take a fairly scientific approach to why things happen and how they happen. I don't know if there's a god or not, but I think religious principles are quite valid.
Gates was profiled in a January 13, 1996 TIME magazine cover story. Here are some excerpts compiled by the Drudge Report:
"Isn't there something special, perhaps even divine, about the human soul?" interviewer Walter Isaacson asks Gates "His face suddenly becomes expressionless," writes Isaacson, "his squeaky voice turns toneless, and he folds his arms across his belly and vigorously rocks back and forth in a mannerism that has become so mimicked at MICROSOFT that a meeting there can resemble a round table of ecstatic rabbis."
"I don't have any evidence on that," answers Gates. "I don't have any evidence of that."
He later states, "Just in terms of allocation of time resources, religion is not very efficient. There's a lot more I could be doing on a Sunday morning."
Bill Gates - Celebrity Atheist List