Evolution of Religion

This is an interesting post over at Marginal Revolution that compares Christianity with Islam. The thrust is this:

My point is not to argue that Christianity or Islam are either more or less compatible with capitalism or liberal democracy. In my view all religions of reasonable age and numbers contain traditions and teachings compatible with modernity and all religions of reasonable age and numbers contain traditions and teachings incompatible with modernity. Call it the completeness theorem.

I'd like to believe that's true, but I have my doubts. Read the post and judge for yourself -- also be sure to read the comments section.