If there's not even good evidence, let alone proof of God's existence, religious faith would be more like blind, irrational hope. That would have many unwelcome implications for proselytizing theists. They often want to say instead that we can learn about God from his handiwork, so there would be indirect evidence for God. If God leaves us no sign of his supernatural priority at all, God's indistinguishable from nothing.

Then again, mystics say the point isn't to boast about having the correct religious beliefs, but to become a spiritual person.