Although over half the world' population are theists (according to Pew survey results), God's existence isn't an obvious fact, not even to those who sincerely believe he exists. To put it differently, as Keith DeRose recently put it, even if God exists, we don't know that he does. This presents a puzzle for theists: why doesn't God make his existence more unambiguously known? The problem of divine hiddenness has long been recognized by theists (for instance, Psalm 22), but only fairly recently has it become the focus of debate in philosophy of religion.
In several works, J.L. Schellenberg has argued that divine hiddenness constitutes evidence against God's existence. A simple version of this argument goes as follows (Schellenberg 1993, 83):
- If there is a God, he is perfectly loving.
- If a perfectly loving God exists, reasonable non-belief in the existence of God does not occur
- Reasonable non-belief in the existence of God does occur.
- No perfectly loving God exists.
- There is no God.
The controversial premises are 2 and 3. Authors like Swinburne and Murray have argued against premise 2: God may have reasons to make his existence less obviously true. Their arguments state that if we knew God existed, we wouldn't be able to make morally significant choices. This is an empirical claim. Obviously, it cannot be experimentally tested directly. However, research in the cognitive science of religion (CSR) on the relationship between belief in God and morality may indicate whether or not this is a plausible claim.