I was searching for the name of the city that Jesus rode into on an ass (for purposes nearly as irreverent) when I happened across this image.
This is a prime time to enter into the discourse the term pareidolia, which is a term which describes the tendency of weak and random stimuli producing a strong recognition response. When you see strange shapes in the clouds or faces in a carpetor you severely mishear English words in or out of foreign languages or in the static whispers of blank audiotapes, or in this case, the form of Jesus in a dog's ass, you're experiencing pareidolia.
Science supposedly has recently found evolutionary advantage in superstition on the basis that responses to imagined or unrelated stimuli may have spared the lives of animals by causing them to react to the imagined presence of predators, thus potentially saving them at a critical time when the predator would have gone unnoticed. This is probably most noticeably in the observable behavior of house cats who occasionally stare at a point nearby in space as if it were their greatest foe and flee or suddenly attack a sock.
It occurs to me that pareidolia may serve a similar purpose in humans. While it made it easier for us to recognize the patterns of our allies, enemies and prey, it also served to cause us to perceive enemies where none existed, potentially saving us in those occasions where the spurious recognition was coincidentally true. Superstition and pareidolia go hand-in-hand, and is most especially noticeable when we are children. The forms we perceive in the darkened room, our belief that something haunts our closet and under our bed, and our general overarching terror of anything we cannot see in our formative years is most likely an adaptation - our odds of survival were greatly increased if we had the good sense to run to mom and dad when it was too dark to spot predators.
It is also given free rein with certain kinds of blindness, resulting in a condition known as Charles Bonnet Syndrome or in the midst of a really good trip (or really bad fever.) There are always those who will see The Virgin Mary in a piece of toast or Jesus Christ himself in a moldy shower curtain (or Lenin) and be willing to drop some serious loot on it.
It's not all religious experiences and medically-caused hallucinations though. Some people like to have fun with the phenomenon.
Me, I think I'll try making a toast printer and earn some e-bay cash.