Well, there are some questions I don't know how to answer without God as an axiom. Specifically, I've never heard a compelling case for the meaning of life that doesn't rely on a transcendent God, which is an important anchor when you're talking about fulfilling human purpose. A belief in the goodness of the world is also most strongly backed by a belief in the Christian God (rather than a pantheistic consciousness) because of the doctrines of creatio ex nihilo and incarnation. But I'll try to explain all that in a way that isn't dogmatic, but reasonable.