"I fear the disapproval of God more than I fear your disapproval or the disapproval of society," Warren, of Saddleback Church in Lake Forest, Calif., told the host of "Piers Morgan Live."
Warren appeared on the show amid a media blitz for his new book "The Daniel Plan" about getting healthy for the glory of God, but his stand for biblical marriage continues to draw attention.
"Have you moved at all now? Are you recognizing that there is this seemingly unstoppable movement?" Morgan asked Warren during the show that aired Dec. 6.
Warren responded, "Well, I don't get to change what God says is right and what God says is wrong. And I think God is real clear that all sex outside of marriage is wrong. But the issue here is the issue of respect. While I may disagree with you on your views on sexuality, it does not give me a right to demean you, to demoralize you, to defame you, to turn you into a demon.
"Tolerance, Piers, used to mean we treat each other with mutual respect even if we have major disagreements," Warren said. "Today tolerance has been changed to mean all ideas are equally valid. Well, that's nonsense. All ideas are not equally valid. You could say the moon is made of cheese and I could say the moon is made of beans and somebody else could say it's made of rocks."
Morgan asked whether Warren believes in "equality for all," and Warren said he does.
"How can you really, as a Christian man, a great man, how can you espouse genuine equality if you don't allow gay people the same rights to get married as straight people?" Morgan asked.
Warren said he's more "against the redefinition of the term 'marriage' than anything else."
"I don't think other groups get an opportunity to redefine a term. For instance, if a Muslim says this is a term we use and all a sudden I take that term and mean it for me, that's not right," Warren said.
"I think historically around the world the vast majority of people would say marriage means one man and one woman in a commitment," Warren said. "Don't take a term and make it something different."
Warren noted that it's not against the law for people to love whoever they choose. He just doesn't believe they are entitled to hijack a term.
"But that term is from the Bible, right?" Morgan asked.
"Well, certainly the Bible says God created marriage," Warren said.
"My issue with that," Morgan said, "is there are many things in the Bible which simply today wouldn't fly. If you were to look at me in a lustful way or any woman in this audience, according to the Bible you should be stoned to death. Clearly we don't do that anymore, so there are a number of things in the Bible which seem very anachronistic."
Morgan wanted to know whether Warren expects to change his mind on the issue of gay marriage.
"You're a man under -- he has this incredible library, Rick Warren. Literally one of the great libraries I've ever seen in my life, kept beautifully. You have all these books by all these great scholars," Morgan said. "Many, many of them will have evolved their thought processes over things depending on how they see things.
"Can you see a time where not just you but other Christian preachers and indeed the Catholic Church and others say, 'You know what? Actually, real equality means everyone has the same right to get married, gay or straight,'" Morgan said.
Warren replied, "I cannot see that happening in my life. I fear the disapproval of God more than I fear your disapproval or the disapproval of society."