I would say that for many people, the supernatural is the maximum degree of rati

I would say that for many people, the supernatural is the maximum degree of rationalism possible, because it is the maximum criticism they are able to perform, with the maximum trust they are able to invest.

morality remains constant across the spectrum of intelligence, but religiosity (abandonment of reason and calculation) increases as intelligence declines, and ethics (reliance on reason and calculation) increases as intelligence increases.

The problem for christianity is the same problem with government. Instead of adding literatures (already extant), meaning history, and natural law, the church doubled down on mysticism.

Natural law is enough. The teachings of Jesus (as few as they are) are reducible to natural law. There is no reason that the church does not teach the truth as a competitor to the lies of the state and the burghers.

But the CHURCH CHOSE LIES. And that is why it dies.