In the novel Lord of the Flies by William Golding, the author examines the idea of the religion of Christianity and how far it influences the goodness in mankind's humanity when enforced behavior limitations are stripped away. Allegory can be an extended metaphor - strong visual imagery that the reader understands. For example, the gradual decomposing of the layers of the choirboys costumes could be read as the slow degeneration of the Christian/Establishment niceties that render civilization calm and pleasant. Many English boarding schools at that time were run on strict Christian principles, but it didn't take long for them to wear off when the boys had "freedom" of choice. it is the author's purpose to show this.
I think that the author is trying to use the religious allegory to back up the major point of the book as a whole. In my opinion, the major point of the book is that human nature is pretty much evil. If left in a state where there is no civilization, human beings will revert to evil.
To me, the major religious allegory is the story of Simon. Simon can be read as an analogy for Jesus Christ. He tries to act in a moral way in a world of sin. But, because of what human nature is, he gets killed.
In the book The Lord of the Flies Golding is demonstrating the concept of good versus evil. Simon is the representation of Christ in the story. He goes off and meditates by himself. He is also the one who has the mental conversation with the beasts. e is killed by the collective group just as Christ was and when he is brought out into the water some type of sea entity surrounds him making him glow.
Jack is the boy who succumbs to the dark side of humanity. He loses all of his moral codes and succumbs to evil. He becomes evil. Roger is another boy who becomes evil.
Ralph is the part of humanity that fights to remain good in the face of evil. He could have left Piggy and gone with Jack, but he knows inside that Jack's behavior is wrong.