Snyder tells CNN, "The Christ-like parallels, I didn't make that stuff up. We weren't like, 'Hey, let's add this!' That stuff is there, in the mythology. That is the tried-and-true Superman metaphor. So rather than be snarky and say that doesn't exist, we thought it would be fun to allow that mythology to be woven through."
In case you don't follow Superman's mythology, the Christ connection starts right at his birth. Kal-El, his Kryptonian name, was considered a miracle on his home planet - due to the fact that other children were meticulously selected via genetics and Superman was born the old-fashioned way. He was then jetted off as his planet exploded (okay, so that's a slight deviation from Christ).
Superman was raised by two simple farmers Martha and Jonathan (cough-Mary and Joseph-cough) and he doesn't reveal who is he, at least his super alter-ego, until he is much older. Superman has died in the comics, only to return to life, but that's a separate story line to the one in Man of Steel.
Snyder also says his film is a closer look at Superman, saying, "He's reinvented anew. He's more down to earth, even though he's also this larger-than-life, impossible figure. Our thesis was, look through Superman's eyes. Feel what he feels. That's where we started, and once you do that, you're in different territory, and that organically changed stuff along the way for us. This exists beyond what I'm going to do here, and what someone else would do beyond me. I really wanted there to be an echo of that throughout the film, and enshrine it for all time."