This reminds of a "proof of God" that appeared (I think) in Seven Ages of Madness by Svend Aage Madsen:
If God exists, then there must be some way to realize what the true religion is. Some hint or pointer that would make it clear, and this hint would be available to all humans. Some people would not understand it, or ignore it, but everywhere in the world, a few people would choose to follow the correct religion.
There are many religions in the world, but only one is universal: non-belief. In some places they are few and far between, but everywhere you find a few people who don't believe in God. For all other religions there are places in the world where that religion is simply not present. But every place has a few people who don't believe. These people must have correctly understood God's hint.
Hence, if God exists, atheism is the true religion.
If God exists, then there must be some way to realize what the true religion is. Some hint or pointer that would make it clear, and this hint would be available to all humans. Some people would not understand it, or ignore it, but everywhere in the world, a few people would choose to follow the correct religion.
There are many religions in the world, but only one is universal: non-belief. In some places they are few and far between, but everywhere you find a few people who don't believe in God. For all other religions there are places in the world where that religion is simply not present. But every place has a few people who don't believe. These people must have correctly understood God's hint.
Hence, if God exists, atheism is the true religion.