Is there a god or not? No one can know, no one can prove, so auguring about this is stupid and leads no where. Is believing in god (religion) bad? Much more interesting question. Back then, in its basics, religion was a good tool to give people guidelines for whats right or wrong. Don't kill, don't steal, don't be greedy, don't be evil... All enforced by fear, like being tortured in hell after death, but overall not much different than what our current law+judiciary system is supposed to do. Giving people rules for daily live, and make em fear the consequences for not following this rules. In times where killing someone for offending you wasn't much of a thing, in times where we hadn't laws and law enforcement like now, this wasn't such a bad thing. On the other hand, religion was often abused as a tool for evil things (wars, genocide...). But its questionable if all this things wouldn't have happened without religion, or if they would have simple used something different as tool to persuade the people to follow em, like the Nazis did for example. Even if there isn't a god, is it wrong to believe in it? I don't think so... Same as non-existent substances in pills help ill people to get well as long they believe they are there (placebos), a non-existent god can help people to cope with problems, go trough hard times, and master their lives, no?