If the main message of all religions is love and acceptance, Why does it causes so much war, bloodshed and violence?

IMHO the reason so much bloodshed has resulted from the practice of religions has less to do with the religions in question, or their message, and more to do with the human fallibility of the followers (and leaders) of those religions and how they interpret the texts of their religion. These days many have expressed negative opinions for example about Islam. Some go so far as to claim the entire religion is one of violent proselytizing, trying to force all non-Muslims into becoming Muslim, by force if needed.

This is in my opinion a vile mis-representation, generalizing from the violent and inhuman preaching and actions of a tiny minority of Muslims to tar with a single brush over a billion of the Muslim faithful who practice their religion with humility and devotion to Allah and all people, be they Muslim or not. Similarly, many other religions have at one point or another been singled out by hateful people and unjustly blamed for terrible things. This is true of Judaism, Christianity, Wicca, etc.The problem is one of being willing to see your fellow man (or woman) as human, fallible, and deserving of compassion, regardless their religious belief.

Violent people exist in our world, and claim to follow all religions, though they do so in ways that the true followers of those religions would abhor and denounce.

The main MESSAGE of religious groups may be love and acceptance, but the true PURPOSE of such a group is to control and influence others. Such a plan will always generate bloodshed and violence from both those being controlled and other groups who want to take control. This is all about power relationships and "religion" is merely the marketing front -- the lipstick on the pig, so to say.

I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.