Religion is one of the main themes throughout both The Stranger and Chronicle of a Death Fortold. Even if in one it is a very important thing, and non existent in the other, both novels somewhat revolve around religion. The novels show how important religion was to most everyone in both of the societys shown each book.
In The Stranger, Meursault does not belive in religion. He rejected it in its entirety. He is punished for this exact thing, being that the court persecuted him for not being a religious man more than they did for killing someone. The entire court case was primarily based on this issue. Meursault felt so strongly about it that he never did change his mind about the matter, even if it saved his life, and when the court attempted to force religion onto him.
In Chronicle of a Death Fortold religion is a very important to everyone.
The coming of the Bishop was a tremendously joyous thing for everyone in the town. Everyone got ready and went to go see him pass, even though he didn't even stop his boat. There was also less obvious religios themes in the book. For example, one being the way that Santiago Nasar was pinned against the wall in a Christ like way, in the shape of a crusafix.
Is is obvious that religion is apparent in both the novels in a big way. It shows how committed people were in the societies to religion, and how important it was to most everyone.