Last week's guest post on cosmologist's and General Relativity Expert's Sean Carroll's blog is by another prominent cosmologist, Don Page. Don argues for God and Christianity on Bayesian reasons:

I tend to favor a Bayesian approach in which one assigns prior probabilities based on simplicity and then weights these by the likelihoods (the probabilities that different theories assign to our observations) to get, when the product is normalized by dividing by the sum of the products for all theories, the posterior probabilities for the theories. [...]

For me, when I consider evidence from cosmology and physics, I find it remarkable that it seems consistent with all we know that the ultimate theory might be extremely simple and yet lead to sentient experiences such as ours. [...]

One might think that adding the hypothesis that the world (all that exists) includes God would make the theory for the entire world more complex, but it is not obvious that is the case, since it might be that God is even simpler than the universe, so that one would get a simpler explanation starting with God than starting with just the universe. [...]

...I have postulated that God loves mathematical elegance, as well as loving to create sentient beings, so something like this might explain both why the laws of physics, and the quantum state of the universe, and the rules for getting from those to the probabilities of observations, seem much simpler than they might have been, and why there are sentient experiences with a rather high degree of order. However, I admit there is a lot of logically possible variation on what God’s nature could be, so that it seems to me that at least we humans have to take that nature as a brute fact, analogous to the way naturalists would have to take the laws of physics and other aspects of the natural universe as brute facts. I don’t think either theism or naturalism solves this problem, so it seems to me rather a matter of faith which makes more progress toward solving it.

To me this post reads like a fascinating case of cognitive dissonance, self-deception, and rationalization. But maybe this is because I failed to construct a coherent argument for the other side. Unfortunately, I have a similar feeling about fervent proponents of Many Worlds, including Sean Carroll himself and Eliezer Yudkowsky, despite having a lot of respect for both of them. I suspect that my desire to discount anything Don Page says about God cannot be trusted, since it feels almost exactly the same way. Knowing that several prominent participants in the LW-rationalist community are also openly or not-so-openly religious makes it even harder to trust my intuition on the subject. Or maybe I should just go with my intuition and decline to listen to arguments for either until there are some solid testable predictions, not just a bunch of handwavey "logic".