If the question is about the opening of the 'Beach of Falesa', then you are right about religion. Religion pops up in the start, with the Papist/Baptist talk, but it doesn't strike me as central to the opening. In the 'Beach of Falesa', he starts with a paradise island, then quickly drags us into the characters, illnesses, conflicts, etc, in a whirl, taking us far from the paradise image, into a much more real and complex world in a few paragraphs, with mystery illnesses that kill overnight and a place where people don't live 'to windward' of the village, but no one knows why. This story begins 'in media res' (starts in the middle at the begining), so you are sucked in as you wnat to know more about this person, their station, where they been before, what they're going to be doing on the island, etc. Why does he need a wife? We are bombarded with bits and pieces- names, details. Religion isn't the major theme of the opening- there's an undercurrent, what did the missionaries do and why does he have to get married? The opening leaves us full of questions and wondering where we're going.
RC begins in a very different manner- again, it's a first person anrrative, but it doesn't launch into telling the story in the middle. he gives us his background, his family, his roots, why he went to sea, etc. Religion is more prominent here- not asking for blessing before boarding, the references to Jonah. But again, if the question is about the opening, I feel that RC is more about painting the picture of the person so that we can see what happens when they do end up stuck on an island. The world around him is painted in moe detail, so that we can see what happens when it is stripped away.
In the Beach, we see a complex society, where people of different races are white, where wives are commodities, where people have long pasts and grudges. In RC, we see a slower buidling up of details about a person so that we will see that person better when the setting changes so drastically.
