I suggest you read the entire post, where some of the Christian allegory in the movie is explained. Here is a small sample:
The movie focuses on the origins of Superman, who was sent from the planet Krypton as an infant to save his species.
He is raised by surrogate parents who help him grapple with his special powers, even though they don’t fully understand the source of his extraordinary abilities.
When he turns 33, Superman must willingly sacrifice himself to save the human race.Of course the Miami Herald argues for Superman's Jewish roots:
Much as the baby prophet was floated in a reed basket by a mother desperate to spare him from an Egyptian Pharaoh’s death warrant, so moments before Kal-El’s planet blew up, his doomed parents tucked him into a spaceship that rocketed him to the safety of Earth. Both babies were rescued by non-Jews and raised in foreign cultures — Kal-El by Kansas farmers named Kent — and all the adoptive parents quickly learned how exceptional their foundlings were. The narratives of Krypton’s birth and death borrowed the language of Genesis. Kal-El’s escape to Earth was the story of Exodus.Clues mounted from there. The three legs of the Superman myth — truth, justice and the American way — are straight out of the Mishnah. “The world,” it reads, “endures on three things: justice, truth and peace.” The explosion of Krypton conjures up images from the mystical Kabbalah where the divine vessel was shattered, and Jews were called on to perform tikkun haolam by repairing the vessel and the world.