A man kneels in a hospital chapel. His daughter is upstairs in surgery. He prays. The prayer is to someone or something larger than him who can hear, who can intervene, who can make the surgery go well. He has never met this larger someone. He's prayed before. Sometimes the prayers were answered. Sometimes not. The pattern of answered and unanswered prayers maps onto chance. The pattern doesn't shake the belief. The belief isn't about the surgery.
K's observation about God was anthropological, not theological. The fragment, alone, invents a larger fragment to belong to. The God is shaped like the hole in the worshipper. The omnipotent God is shaped like the worshipper's helplessness. The loving God is shaped like the worshipper's need for love. The all-knowing God is shaped like the worshipper's confusion. Every divine attribute is a precise inverse of a human deficit.
This isn't to say there is or isn't a God. K wasn't a polemicist. He was a phenomenologist of the religious move. The move is: the fragment, feeling small and isolated, projects a larger version of itself onto the universe, and prays toward the projection. The prayer feels like reaching out. Structurally it's the fragment talking to a magnified mirror. The mirror has whatever shape the fragment needs.
There's a particular comfort in prayer that isn't about being heard. It's about no longer being alone. The fragment, in prayer, isn't a fragment. It's a fragment in relation to a presence. The presence is constructed, but the relation is real to the body. The body relaxes when the presence is there. That relaxation is the real benefit of prayer. The presence may or may not be there in any other sense.
The God is shaped like the hole in the worshipper. K wasn't saying don't pray. He was saying notice what's being prayed to, and notice that the shape is your own deficit, inverted. The fragment, alone, invents a larger fragment to belong to. The larger fragment is comfort. The comfort is real. The larger fragment may not be.