Ok, just to be clear, this is not a theory, just some thoughts and comparisons. Also, I know that some of you don't approve of discussing religion on this website, but Christianity is a major theme in Lost. I just noted a few parallels between Jesus' story, and Jack and Christian.
- First, Christian's name is an obvious reference to Jesus. Jesus = the Christian "Shepherd". Jack, also means "God is gracious".
- Next, think about the symbolism of Christian opening the doors of the church at the end of the finale. Some people interpreted the "moving on" scene as going to heaven, with the Flash Sideways being purgatory. When Jesus died, he "opened the doors to heaven". When Christian died, he literally opened the doors to what some people interpret as heaven.
- Also, Christian appeared to Jack on the island, in times of...importance/struggle. Christianity teaches that Jesus/God comes to you in bad times. Now, you can argue that it wasn't Christian, because according to MiB, it was him in Christian's form, but either way, Christian (or someone in his form) came to Jack.
- Ok, now this is different. You could also think of Jack as Jesus. He was sent by his father (if you think about it, Jack never would have gotten on the plane if Christian hadn't of died) to a new "world", and he ended up suffering and dying to save his people. (Well, they were his people when he was the protector.)
There's probably some stuff I missed. What do ya'll think?