The following quotes show the conflict between good versus evil as a conflict between characters who embody those traits.
“All them other kids,” the fat boy went on. “Some of them must have got out. They must have, mustn’t they?”
In this phrase Piggy was showing concern for the other kids on the same plane, which also showed his kind nature. The plane had crashed and the two boys were making their way out of the wreckage.
“We can use this to call the others. Have a meeting. They’ll come when they hear us—”
Piggy and Ralph had found a conch shell and Piggy suggested they use it to call for other survivors. The conch shell later evolved into a symbol of authority and order among the group of kids.
“You’re talking too much,” said Jack Merridew. “Shut up, Fatty.”
“He’s not Fatty,” cried Ralph, “his real name’s Piggy!”
Jack met with Piggy, Ralph, and the other boys, but while they were introducing each other, Jack insulted Piggy and Ralph stepped in to defend Piggy. This initial confrontation determined their character inclinations with Ralph representing good and Jack representing evil.
“He says the beastie came in the dark.”
One of the younger kids tried to explain an encounter with a monster at night. The snake-like creature (beastie) was a symbol of evil on the island and led to confrontations between Ralph and Jack.
“You would, would you? Fatty!”
Ralph made a step forward and Jack smacked Piggy’s head. Piggy’s glasses flew off and tinkled on the rocks. Piggy cried out in terror:
Jack physically attacked Piggy after Piggy confronted him about the signal fire that was extinguished.