What religious imagery in Lord of the Flies shows a fall from grace, a savior, and redemption?

Whenever you're talking religion in Lord of the Flies,
you're talking about Simon. And the key chapter for religious imagery is the one in
which he climbs the mountain to discover that the beast is in fact just a dead
parachutist, shot down in the war raging back in the real
world.

The parachutist himself represents a fall from grace
(as perhaps, do the boys themselves, falling in a crashed plane onto the island).
Golding deliberately moves, at the end of Chapter 5, from the wailing littluns to the
parachutist's descent: civilisation on the island has very clearly descended towards
savagery. Here's the parachutist, described just after the littluns have
cried:

There
was a sudden bright explosion and a corkscrew trail across the sky; then darkness again
and stars. There was a speck above the island, a figure dropping swiftly beneath a
parachute, a figure that hung with dangling limbs. The changing winds of various
altitudes took the figure where they
would.

This figure terrifies
the boys, and Simon, of course, is their saviour - or he would be, if they didn't kill
him (sound Christ-like? It's supposed to). Simon's knowledge of the parachutist would
save the boys from fear; but they kill him out of fear, thinking he's the beast. And as
he dies, he's uttering the truth - which, ironically, could be both a description of the
parachutist and a reference to Christ's crucifixion in the
Bible:

Simon
was crying out something about a dead man on a
hill.

Simon, the redeemer, is
himself redeemed by nature once his attempted redemption has failed. In a beautiful
description, Golding has the dead body of the boy taken back into the bosom of nature -
a kind of redemptive calm after the horror of his
death:

The
water rose further and dressed Simon's coarse hair with brightness. The line of his
cheek silvered and the turn of his shoulder became sculptured marble. The strange,
attendant creatures, with their fiery eyes and trailing vapours, busied themselves round
his head. The body lifted a fraction of an inch from the sand and a bubble of air
escaped from the mouth with a wet plop. Then it turned gently in the
water.

Notice, of course, the
bright creatures around Simon's head. They'd look a bit like...  a
halo.