Joe Carter has a typically thoughtful review of Lost and the Christ-figure of Jack:
In case that is too subtle, the producers also gave him a name with a Biblical allusion (the Good Shepherd), a father whose name screams God-figure (Christian Shephard), have him drink from a cup in the garden after submitting his own will to the higher purpose, give him holy wounds in his side in a fight with the Devil, and then have him sacrifice his life for both his friends and enemies. No doubt the producers would have called the character “Jesus Christ” had their lawyers not warned that the name might already be trademarked.But Joe doesn’t think it ultimately works:
Although the show’s creators recognize the value in having a Christ-figure, they fail to understand the significance and purpose of the actual figure of Christ. They’ve seen the archetype used in movies (e.g., Neo in The Matrix) and literature (e.g., Simon in the Lord of the Flies) and assumed that merely having a Christ-figure in the story was enough to tap into a Jungian collective unconscious. But because they fail to appreciate how the death of Christ affects the metanarrative of history, they do not realize how their Christ-figure is supposed to affect the narrative of their own plot.More:
Lost replicates many of these tropes (God the Father—Christian Shephard; the created but fallen world—the Island; death of Christ—the sacrifice of Jack; Kingdom of God—the afterlife in the church) but is unable to connect them because of an inadequate concept of sin. . . . The result is that the two primary deus ex machinas of Lost are rendered irrelevant: Where there is no sin there is no need for either Christ or purgatory.You can read the whole thing here.