Religions are a good antidepressant for people who for some reason can't handle some stuff in their life (and let's be honest - majority can't..). If not religion then alcohol/drugs or antidepressants. It thrives on a human nature, that's why it's so widespread and ageless. Many people juct can't deal with a reality and religion works as a "feel good" tool to reduce the stress, reduce the fear of death, the fear of living (and facing difficulties), just generally calms down. The issue is - there's no artificial way that makes humans "feel good" that doesn't cause problems on a long run.
Atheists are people who are too smart for these illusions, people who dare to face the factual reality, and that's not an easy way out, not a plasurable one (like being "buzzed" by alco, drugs or religiion), simetimes I'm jealous of people still believing in Santa.. I mean - Jesus/Allah or any other imaginary friend.