G. K. Chesterton makes the case for atheism

I just reread The Innocence of Father Brown, a series of little murder mysteries set in upper-class British I guess fin-de-siècle society. The protagonist is a plain little Catholic priest who's much smarter and righter than everybody else; it becomes a bit grating quickly. When I read the book many years ago I had the sense of the argument it makes for Catholicism. Now, noting how Chesterton deals with the secondary characters (an atheist murders a man about to give money to the church; a charismatic sun-worshiper is an American fraud/murderer; a Hindu wants only pure annihilation; an Anglican curate is a murderer, and the Presbyterian blacksmith is maniacally intolerant) I have a sense of a man desperate to be right.