Tintinrulz:
The Madwoman of the Sacred Heart (although being a Christian it may best to avoid it). Does it poke fun at religion or God himself? The former I can handle, but not the latter.
It's been years since I read it so I can't be sure, and I'm not sure I'd know what would count as poking fun at god either. However, reading the back I see the publisher describe it as a "thought-provoking, often sacrilegious, tale of faith and lust" so I'd guess it isn't for you.
On the plus side though: no cowboys!
George