Camus is critical of Christianity in The Plague. In chapter 11, when the people flock to church to hear Father Paneloux's words on the cause of the plague and what to do about it, his ideas are not helpful.
First, the plague, Father Paneloux says, is due to people's sin. God is punishing the guilty for their crimes. Yet, as many critics have noted, while Father Paneloux fills his congregation with a sense of guilt, he himself takes no responsibility for the church's participation in sin: it is "you" who have sinned, he tells them, not "we."
Using what to Camus's mind is a false logic to explain the plague as punishment for sin, Paneloux only contributes to the panic. And finally, after all his vivid fire and brimstone talk, Paneloux's ending words, calling for brotherly love, are insipid. In fact, by the following day, the sermon's impact is already weakening, leading to apathy.
Camus's point is that conventional religion misleads people with false solutions and is inadequate to the task at hand. Suffering in the end is not due to sin. Suffering makes no sense. Vague calls to brotherly love lead to apathy. Better help is found in concrete action.