There’s a difference between how we know something to be true (epistemology), and what makes that something true (ontology). Keeping this distinction in mind would illuminate many debates. For example, atheists often claim that one doesn’t need God to know morality and act morally. That’s true, but it misses the point. Just because one can know moral truths and behave morally without believing in God does not mean God is not necessary to explain morality. As Greg Koukl likes to say, that’s like saying because one is able to read books without believing in authors, authors are not necessary to explain the origin of books (author-of-the-gaps). In the same way books need authors, moral laws need a moral-law giver.
While both atheists and theists can have knowledge of what is good/right and act morally independent of belief in God (epistemology), atheists cannot make sense of why there is such a thing as morality apart from the existence of God. While belief in God is not required to have moral knowledge, the existence of God is required in order for there to even be moral truths in the first place. See the following blog posts I authored for more information on this topic: