Faith is bad for it can be the key to violence so easily.  It is also bad for it often is the key.

If you submit to a higher power in faith be it luck or God, you are letting it impose on you and by extension on other people. You are a social creature and what happens to you will affect somebody else.  Imposing is low level violence and it is always how the gate to something worse is opened.

Religion is manipulative for as it depends on people bringing it its babies as members and giving it money and a hearing it cannot let its love of violence be too obvious.

Witches are believed to want to believe in magic because rather than accept what comes in life and what cannot be changed they want to harm enemies secretly by occult means.  Pity a study was not done to see to what extent prayer attracts believers who want to use it for the same reason.

Religion needs to be measured for passive aggression.  Here is how it can use that aggression to cause a lust for war and use it in a crafty way while pretending to be all for peace.

By giving us something we don't need, do you need prayers as much as you need clean water?, as if there is not already enough for people to fall out over and accuse each other of stupidity and lying over.

By giving people an identity that is different from others leading to an us versus them approach. (Religion is often far more a matter of identity than it is a matter of beliefs and practices. That is why even those who have barely any religious belief will still wage war to promote Islam or Christianity. People of different countries can slaughter and hate each other over identity. Religion is another excuse as if we don't have enough trouble with patriotism.) When Catholics, for example, have a problem with Islamist fanatics, the Catholics will see themselves as defending themselves against an enemy. It is more about us versus them than about the Islamists' behaviour. Their behaviour serves as a trigger for the us versus them mentality that is the one essential when you want people to start a religious war. Bad behaviour then in one religion leads to psychological attraction to inter-faith violence in others.  The problem with those who say “us versus them” is bad is that nobody can get on with everybody or every group. And it PRETENDS to assume we can and should all get along though we know it cannot be done. Those who say a religion cannot be condemned for the evil actions of a few members are creating an us versus them.  The them will comprise those who know that religion has to be blamed for helping the evil to happen by failing to attract the members effectively towards goodness.
 
By teaching that evil violent books are God's word - a religion that does no harm but which promotes scriptures that advocate harm in the name of God is still to blame for the actions of those who decide to obey those scriptures. If it calls them extremists then it is just being do-gooderish and hypocritical. If you carry out violence for you feel that your scripture says violence for God is not a big deal, then you are NOT AN EXTREMIST for your interpretation could be correct! The extremist label is often used to make out that the violent are distorting their religion and that there is no violence authorised in the religion's scriptures. The violent would only feel encouraged when people are so hypocritical.

By teaching that the wrongness of fighting for God is reduced and made more tolerable because it is done for God. So war over oil is intolerable and unjust but if it is over God then it is not as bad. It is not as bad for the same reason as terrorism is not as bad if it is done because you love your leader than if you do it to get money. It is not justified but it is less bad.
 
By being religion. Religion unlike everything else has to be totally pacifist and that is the only thing that restrains the violent urge. If it ever condones violence at all it creates a slippery slope we could do without for there is enough. The problem indicates that there is something that religion does to people to make them tend to violence.
 
By accepting (and thus enabling) war mongers as full members of the faith. In Catholicism, you are barred from communion and the Vatican bank for atheism but not for war-mongering.
 
By being a form of culture. Things like honour killing among Muslims may be described as a cultural problem and not a religious one. All agree that culture can be religious but few realise that religion is simply a different kind of culture. It is culture when it claims to be sanctioned by God. It is fashionable to say that culture can cause divisions and hatred between nations. Culture and religion are both dangerous. Religious culture is worse than secular culture for the latter should at least in principle be willing to learn and improve for it does not claim to have backing from God and the supernatural. If culture says the bride must wear blue, that is not as harmful as when the culture says God will hurt her if she doesn't so she must wear it. The latter is pretending that the man-made rules of culture are made by God and must not be questioned even if they cause fear and intimidate.
 
By prayer. Petitionary prayer is making yourself feel you have done good when you have not - you ask God to do the work and you feel good about that or you feel good simply because you prayed.  Traumatised people feel a lot better if they talk to somebody so prayer can be trying to deal with how you feel about somebody's suffering and the result is you are under a placebo.  Worship is bad for it is unduly risking praising God for wrongly letting people suffer. People who like prayer get the buzz. That is why they like prayer. It has led to the extraordinary spectacle of terrorists and abortionist Catholics coping with the evil they do by saying prayers. Prayer is a placebo for evil-doing. Evil Muslims who have killed and maimed over Islam are portrayed as bad Muslims who are only pretending to act in the name of their faith. And this despite the fact that they pray often and pray during their time in jail and express no repentance. They still have a religious motivation.
 
By advocating a way to feel in control instead of feeling subject to blind and perhaps harmful forces. The believer in God feels that God will let things happen that will hurt him or her. So he or she deals with this by accepting the will of God and this wins a sense of being in control. It has been noted by many that really good people turn evil when they feel safe enough to do the evil they want to do. Absolute power corrupts absolutely. Feeling God is with you is the ultimate way to feel you are absolutely safe and thus that you as good as have absolute power.
 
By advocating the notion that suffering produces virtue or should be turned into a means of being a better person. Seeing yourself as helping the people you persecute when you make them suffer is dangerous. It enables religious war. It acts as a placebo for the conscience. The more you kill the easier it will become to justify it in your head. If there is a God then he will help everybody to grow through suffering. People can grow through suffering even if there is no God. So atheists too can persecute thinking that if the victims don't use their agony to grow in virtue it is their own fault. But the difference is that if there is a God it is everybody's fault if they don't use their suffering well and if there is no God, people are on their own and cannot be blamed if they don't grow. Without God there is no guarantee that they will be able to grow and so the growing does not permit the atheist to persecute them.
 
By advocating a God who paradoxically can be controlled though he cannot! God will do what is right and does not need us to ask him to. Yet the notion of praying to get something from God is foundational to religion. Believers think prayer has power to get God to do what one wants. They are trying to tell God he won't do something good unless they manipulate him by asking him. This results in a good feeling about the future. This feeling can lead to violent believers thinking they can make God approve of their activities. Believers do not want a God who does what he does regardless of what we ask for or don't ask for. Their devotion to God masks idolatry. Believers are expected to feel their prayer has been answered even if it has not been answered yet.
  
By urging that people seriously believe in God. If you are left to suffer at the hands of cruel parents, that will damage you and maybe you will then want to punish others and take it out on them. There will be anger in you. The more you suppress it the more dangerous it can become for it is not obvious. If you feel God has let your parents hurt you, and if you really respond to God like you would a human person or loved one, then horrendous damage will be done to you psychologically. It does not matter if somebody tells you that people had a reason to let your parents hurt you or that God had a reason. It is about the sense of abandonment - reasons will not help. A child is still damaged by a parent who was driven to drink. The parent's lack of responsibility for the alcoholism does not change how the child will feel. It is not a rational matter.
 
By keeping people away from facts and information it does not want them to know - this in itself is a form of totalitarianism. Obscurantism and totalitarianism go together. Could you imagine trying to find a book that refuted the truth-claims of Catholicism in Ireland during the 1950's?
 

By saying that atheists or atheism as in belief subtly draws one to be more open to causing or enabling violence.  A religion that says atheists subtly do that should be checked out in case it is seeing in atheists what it knows exists in itself.  You cannot say that God is important or faith in God without hinting that a negative or disbelieving view of them is somehow harmful perhaps subtly so.
 
By existing - yes religion makes war possible and/or likely merely by existing. Religion becomes more attractive in times and places marked by great violence. People are not turning to it as a natural alternative to violence. They are not turning to it as a natural defence against violence. They are turning to it for they think they will get God to give them more power to vanquish the enemy. They turn to religion then to get supernatural support for their violence.

Religion when it tells you that you need light from God is intrinsically open to the notion that a god or spirit might need you to kill for a superior purpose. But some religions manifest this trait more obviously than others. Atheism is safer when it denies that you should act on anything that seems to be a divine revelation. With religious wars, there are two sides to every story. It is natural for one faith to fear others for the believer is the best judge of the potential dangers of faith and uncertain "certainties".
 
When a faith or religion has too much violence done in its name, then you have to walk. Take it on face value that the religion is doing something that causes that evil. You don't have to know what it is. Go to a better religion if there is one! There are certain things you do not try to find excuses or reasons for. Go by the principle that actions say it louder. What do they say about the religion? Do not collude by being a member. Find the door.
 
Religious as in supernatural faith is definitely the problem. Religion is the problem because it supports and nurtures such faith.  A serious opposition to violence means opposition to anything that MAY lead to it especially when the thing is not that important in itself.