Here Comes the Sun
The sun in Room reminds us of the creepy baby in the sky from the Teletubbies, because Jack always describes it as "God's yellow face" (1.73). For Jack, the moon is God too, specifically "God's silver face that only comes on special occasions" (1.286).
Jack doesn't just think this up out of the blue. It's highly likely this is what his mother taught him, and it shows us how strong their faith is. In Room, faith is one of the only things Ma has to keep herself going, and she passes this on to Jack. She also occasionally occupies her time by reading The Shack, a book all about a loving and accepting God.
Ma passes on her faith that God is the provider, not Old Nick—which, not so coincidentally, folks, is a nickname for Satan. Jack even says that food comes from "Baby Jesus in the fields in Outside" (2.450).