Moral Scepticism

Dr. Craig,
My wife and I have begun to teach an apologetics class at our church, and we invited our class to our house to watch your debate with Alex Rosenberg. We also invited my wife's father, who claims to believe in the Christian God, but is very defensive about morality. He basically believes there are no objective morals, which makes me wonder how he can truly be saved, since the crux of Christianity is about needing God's grace because we have broken objective morality.
Watching your debate got us talking about objective morality and intuition - or as you called it, a "properly basic belief." But when we pressed my father-in-law, he denied that the notion of objective morality was an intuition like other minds. It's difficult to find anyone we'd classify as sane who believes other persons don't exist, yet we can find examples galore of those like Bundy or Hitler who think rape or murder are perfectly fine. In fact, my father-in-law even went so far as to say if a society of Ted Bundys would arise, while he doesn't like the thought of it, he couldn't say it was objectively wrong.
In our discussion, it also seemed like he was hung up on the idea that there was no "list" of morals. The "Ten Commandments" aren't exhaustive, and Jesus's notion of loving God and loving others is too subjective for him. If you can't prove objective morality by providing a knowable, exhaustive list, he's not satisfied. We can see demonstrations of abstract concepts like the addition of numbers, we can empirically test scientific truths, and we can intuitively know that we exist, but objective morality seems to fail all these tests.
He seems to conflate the epistemological struggle of morality with the ontological struggle. However, we're having enough trouble in even showing him that objective morality exists at all. How do you talk to someone who is willing to say that a future society of Ted Bundys wouldn't be objectively wrong? Thank you again for all you do.
United States

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