Many sane, educated and generally trustworthy people claim not only that God exists but also that they have genuine knowledge, including justified true belief, that God exists. Because claims are typically cheap and easy, however, the claim to know that God exists will prompt the following response, usually sooner rather than later: How do they know? This common four-word question, although irksome at times, is perfectly intelligible and even valuable, as far as it goes. It seeks an explanation of how the belief that God exists exceeds mere belief, or opinion, and achieves the status of genuine knowledge. In particular, this question typically seeks an explanation of how, if at all, the belief that God exists is grounded, justified, reasonable, or evidence-based regarding affirmations of truth. A plausible goal behind our four-word question is, at least for many inquirers, to acquire truth in a manner that includes an adequate indication of true belief. These truth-seeking inquirers aim not only to avoid false belief and lucky guesswork, but also to minimize the risk of error in their beliefs (at least in a way befitting to the acquisition of truth). We should aim for the same, as people who seek truth but who are faced sometimes with facts and other realities at odds with our opinions. In seeking truth about God’s existence, in particular, we thus should seek truth based on evidence for God’s reality. Such evidence, if available, would indicate that it is true that God exists, or (in other words) that God is real rather than fictional.   – Paul K. Moser