In his book, I Was Just Wondering, Philip Yancey recounts one of C.S. Lewis’ most interesting arguments for God’s existence. Lewis claimed that only a theistic worldview could explain the existence of dirty jokes.
The argument was pretty simple. If you observe the animal world, reproduction is a rather mundane affair: animals certainly don’t get bashful or embarrassed about it. But we humans, with juvenile smirks and double entendre jokes have always treated it as something out of the ordinary.
Evolutionists don’t have any rationale for this different treatment. Are we supposed to believe that dirty jokes help perpetuate the species? In fact, there is no natural reason to treat sex as anything other than routine. And if there is no reason to see as something special, then there is no reason to tell dirty jokes about it. We don’t tell jokes about common ordinary events.
The Christian rationale for this different treatment is much clearer. Reproduction is something special because God has set it apart from normal human activity and guarded it with rules and requirements. And even while society ignores those rules they still can’t help but recognize that reproduction is something special. They don’t want to honor the rules God has set out, but they can’t help but acknowledge His rules when they set out to mock them with dirty jokes.