We are first introduced to Simon as the boy who faints. Golding is playing on the idea that Simon is epileptic and therefore, according to ancient beliefs, somewhat psychic. This prophetic trait is emphasized later when Simon tells Ralph that "you will get back all right." On the first expedition to explore the island, Simon is the one to recognize the candle buds. Unlike Ralph and Jack who see no value in something that cannot be used or eaten, Simon just likes them for their aroma. This closeness to nature is also emphasized throughout the novel as Simon retreats to his bower and lets the beats of his heart match the rhythms of the waves (end of Chapter 3). In Chapter 3, Simon is the only one who stays with Ralph and helps him build shelters. The others all desert him. In the same chapter, Simon's kindness is also reflected when he picks fruit for the littluns who cannot reach it on the trees. In Chapter 4, he gives Piggy his share of meat when Jack refuses to give Piggy his portion.
To get an idea of how Simon's goodness is contrasted to that of the others, especially Jack, read the opening of Chapter 3 in which Jack is described in detail. Then read the closing of that chapter in which Simon is described in detail. Simon's kindness, thoughtfulness, posture, relationship with nature are consistent with that of a Christ figure. Jack's obsession with hunting and his animal-like posture reflect that of a savage.