There is so much symbolism in this book.
Piggy's glasses- Intelligence, weakness in the eyes of the boys, otherness
The Island- Initially it is a kind of Biblical Eden or oasis. The boys turn it into a literal and figurative Hell (Fire and all!).
The conch- democracy, order, the old world, civilized behavior
The Beast- The Devil, fear, the boys themselves (Simon points this out!)
Face Paint- new identity, leaving the old world, dark side of human soul
Fire/Smoke- Comfort, safety, rescue, power
Pilot guy- The old world, technology, fall of man, perceived beast