  In the town where I'm living for the summer, all the churches have those clever little marquee signs in front. These are not at all common where I come from, so I find them immensely entertaining. Apart from the obvious urlLink Simpson's connotation , they are generally fairly amusing, either from an intention to be so (THIS CHURCH IS PRAYER CONDITIONED) or from their usage of FUD tactics (OBEDIENCE MAY BE COSTLY, BUT DISOBEDIENCE IS MORE COSTLY).
As an urlLink agnostic/atheist , I also found urlLink this rather amusing. And of course there's the ones which were obviously put up by some sweet, innocent church-lady type who is oblivious to the urlLink innuendo . The sad thing is, a friend of mine has seen that same sign in a different region of the country, meaning not only did someone decide to put that up outside a church in the first place, someone else saw it and thought it was appropriately inspirational enough to reuse.
The largest list of these types of pithy sermons that I found is right urlLink here . By the way, I generally have nothing against Christians, or trite sayings, but every single site I found listing funny church signs (including the one I linked to, I'm sorry) had some lame-ass animation on it. 
