Simon,
All religion.I don't agree, Simon. Religion itself can be a belief system for one individual that enhances their life and may even help them value life more.
Imagine how much better society would be without religion? It devalues life IMHO because of the 'god will fix it' mentality and without it people would probably value life a lot more than they do.
Organised religion is a different thing entirely. Yes, organised religion has been extremely damaging throughout history.
Belief itself is not the cause of the horrors. Human beings are the cause. Desire for power, control, and group conformity are part of human nature. We all get together in groups with a common interest (whether that is religion or something else) and we tell each other we are right and that the "other" groups are wrong. Then, we act with the group and diffuse the responsibility of those actions. The product of this is a group who behave more horrifically than most individuals would.
I consider myself to be religious, and I associate with a local group (probably once a month). It is entirely possible to be religious and to not be controlled by the group, in fact its possible to be extremely spiritual without ever meeting anyone else with similar beliefs.
Sirona