Evolution already explains why we feel that way
The objection
Our moral intuitions have an ordinary history. Creatures that protected their young, punished cheats, and cooperated in groups left more descendants than creatures that did not. Over a long time, natural selection would install exactly the feelings we have — powerful revulsion at harming children, strong reactions to betrayal, a sense that these feelings are objective. Michael Ruse and E.O. Wilson argued the illusion of objectivity is itself the adaptive part: an intuition we could shrug off would not do its job. So the universality you find so impressive is precisely what you would predict on a purely natural story, and no God is required anywhere in it.
The response
This is a strong explanation, and Christians should grant everything it actually establishes: there is very likely a natural history behind our moral feelings, and it may be exactly the one described. But notice what it explains. It explains why we have the feelings. It does not touch the question of whether the feelings are ever right about anything. The account works just as well if cruelty is genuinely wrong and if it is not — which means it is not evidence either way about the truth of moral claims. And it comes with a bill. If moral intuition is a useful adaptation and nothing more, then torturing a child for fun is not wrong; it is something our nervous systems were built to hate. Some who hold this view accept that conclusion openly, and their honesty deserves respect. The point of this page is only that the conclusion is the price, and it should be paid in daylight rather than quietly avoided.