In this iconic image, we see Michelangelo's depiction of the "spark of man." At first glance there's nothing really out of the ordinary; it seems to be a straight forward story. However, upon closer inspection, we find that the image of god and his angels in the distinct shape of a human brain. This is no coincidence, the anatomy is near perfect. Michelangelo was known for for being a renaissance man: architecture, anatomy, art, sculpture... the list goes on.
Perhaps his religion was more than church doctrine. He was only a commissionee after all. He may want us to see that god as depicted in Christian beliefs is to him simply the human brain and self consciousness. Perhaps he is saying that is god who gave us intelligence. It's an interesting spin on a classic.