Simon is in many ways set apart as a holy figure who is unlike the other boys. For instance, while he was in Jack's choir at home, he never follows Jack's lead on the island. This suggests that for Simon, the choir was a sincere form of worship, while for Jack it was a way of becoming powerful.
Simon is gentle and centered. Like a Christ figure caring for his sheep, Simon tends to the needs of the vulnerable younger boys. Like Christ, he is concerned about both their material needs for food when they are hungry and their spiritual need for comfort when they have nightmares on the island.
Like Christ, Simon goes off to meditate and commune alone with nature. He has developed an intuitive sense of perception that allows him to see beyond the fears of the other boys and so, like Christ, is not deceived by superstition. He is also able to resist the lure of Jack and his embrace of an atavistic, cruel way of life that revels in destruction.
Simon has a Christlike ability to communicate with the pig's head, which represents Satan's right hand devil, Beelzebub. He speaks out loud to the head when he understands it to be conveying the idea that life is bad, just as Christ speaks to the devil in the desert.
Like Christ, too, Ralph discovers truth and tries to communicate it to the other boys, and, like Christ, he is killed for his pains.