This could be the 1985 novel Empyrion written by Stephen Lawhead, who is a well know writer with a large interest in Celtic Christanity.
The novel is a omnibus edition of The Search for Fiera and The Siege of Dome. The story follows Orion Treet (a writer of history) in his mission to unravel the mystery of the colony world Fiera. Treet isn't young exactly but sometimes comes across that way in the writing I feel.
Orion Treet's job is to observe and chronicle the growth of a new extraterrestrial colony: Empyrion. Arriving on the planet Fierra, Treet discovers a civilization in decline; to survive, he must unscramble its mysteries before time runs out for the settlement.
In the colony, called Dome, there are various castes, and one of which does work with garments. Others are priests of a cult, or administrators or security. Some castes rank "higher" and have more prestige in Dome, or are feared more.
In addition, at one point Treet goes to a Temple to witness a rite that leaves him repulsed IIRC. It has been a fairly long time since I last read the book, so some aspects are a little hazy.