In the last 2011 years and I'm sure eons before that, too many people have died in the name of God, and I just want someone (anyone) to explain religion and faith to me in a way that does NOT fall back to the circular arguments of "I believe because I have faith" (a non-answer/choice) or "I have faith because I was brought up to.." (dogma).
People dying (and more importantly, killing) in the name of God is a secondary, though a powerful, effect of religious belief. Other examples of secondary effects are fear abatement. I'll get back to those sort of things but first the underlying phenomenon.
People are social. That is a very adaptive trait for animals such as ourselves who have (despite the fact that we are at 7 billion now) a low birth rate and an incredibly long pre-adult stage. It really does take a village to raise a child. We don't notice that so much these days because we feel independent when we live in our own house and make a coffee but the interdependence behind such a simple act is for the most part incomprehensible. It takes thousands of people to make that cup of coffee in your house possible. Since we are so dependent on each other we have adapted to relate strongly to other human minds. We even have ways of modelling the minds of others in our own minds so that we can try to figure out what they want, what they are thinking, whether they are deceiving us, whether they might be angry at us and how we could assuage that anger. We can form alliances and secret plots and we can detect alliances and plots against us. We are tuned to human body language and we are very good at reading facial emotive communication.
Since we dedicate so much brain power to these social functions and are so attuned to pulling hints of faces out of a noisy visual environment we often see faces in such things as clouds, burnt toast, mildew stains, though we
usually know that they are not real faces. We are born to see human faces - it is that important to our survival.
Similarly we are born to detect the presence of other thinking minds and often we detect thinking minds in random noisy events of the universe where no such thinking mind exists. We talk to our cars/motorbikes/computers etc. as if they were people though we know they are not - but that doesn't stop us punching the keyboard when the stupid computer is not doing what you want or encouraging your car to keep going when you suddenly see the gas warning light come on and you're miles from home. We have a built in tendency to treat everything as if it had a mind, even the universe itself. It's natural and it feels empowering because we know how to deal with things that have minds - unlike the chaos of nature which can crush you like something less than an ant without caring nor even noticing.
It is a natural tendency, therefore, to "believe" in gods and spirits. We even recreate these "minds" we perceive in the universe in the same way we recreate the minds of people we know well and we can talk to these minds inside our heads - talk to the universe in much the same way as we talk to deceased parents and friends.
The kind of labels and rituals we attach to our "gods" depend on cultural heritage. In the same way that we have a natural tendency to language but the language we speak is the one we learn and which is also the language that everyone around you speaks. It isn't that there is a ONE TRUE LANGUAGE! You won't find a Chinese child growing up in a Chinese village suddenly one day converting to speaking German in some epiphany. Similarly you won't find a Hindu child being raised in a Hindu village suddenly have a revelation and start professing a fully formed faith in Jesus Christ. It's not that the Chinese child can't learn German, he can because he has the ability to learn language; and it's not that the Hindu child can't become a Christian, she has the innate inclination to see agency in the universe. Both language and faith are part of natural human potential but how it manifests is cultural.
Faith is just another word for trust. If you have faith in a friend then you trust them. If you have faith in God then you trust God. Belief in God or belief in your friend are already givens. If you cross a bridge you already believe that the bridge is there, but you have faith that it will hold you up as you cross over. But the bridge may collapse and that will break the faith. However, once you are lying at the bottom of the valley you may look up and realize that the bridge was never really there. Faith and trust are also normal and necessary parts of society - without it groups can't hold together and far fewer things would get done that require cooperation. Even when faith is broken we hate to give up on it entirely because it is so important to keep a group working and sometimes we will rationalize away a broken faith - "it must be because of something that I did" people will assume, and then they will try harder to make it alright again. This can drive some people to have undue faith in faithless people - such as the battered wife who is sure that her husband will become that man he should be if only she tries harder to please him.
But sometimes when your faith is broken again and again it simply means that the faith you have in someone is unjustified because the person you think they are is not the person that they are, or the person you think exists doesn't actually exist. That's the point at which some people will leave their old gods behind them realizing that, while they were a nice story to have as a child, they don't really make practical sense any more.
But now back to faith, in the religious sense, and why people kill and die for it.
The individual benefits of having faith in a god or protecting powerful spirit are that you can, for example, put aside worries over things that you cannot do anything about. You can have faith that your friend will look after those things for you. This means less wasted effort, less stress, more time to focus on the things that you can change.
There is also a benefit on the species level. Humans have spread over the planet on a certain level of fearlessness on the part of explorers. If you can trust that you will be OK then you can leave for hopefully greener pastures. A lot of the time you would become dead but some of the time a small group of people would establish a new colony. Obviously, becoming dead is bad for a person - but the trait over a number of individuals allows the individuals (and therefore the trait) to spread.
There are also benefits to the group. A group with a shared belief in a god, especially a central authority god like the father gods, can be directed en masse and controlled by a small priesthood. While there have been many famous kings and emperors through history they all kept some priests close to hand. The "god" justifies the kings position and the priests convey the kings will as though it were the god's will and while the king is a distant figure on the hill, the god is a close confidant right inside your head.
The ability to compel the unified action of many bodies gives the leader great scope in what he can do and provided that the leader is wise then the lot of the group can be radically improved (though some will have to suffer, be imprisoned, "justly" punished or killed). Further, if the fearlessness of belief is harnessed to the unquestioning obedience to a leader god then people can be directed to kill and plunder - to take to themselves the riches of others and to conquer and acquire new land thus spreading their culture and their people. Groups that can do this the best gradually take over all other groups.
There is a long history to our faiths and to the mechanism by which we have faith and the reason that we have them today is that they proved themselves useful in previous times. They remain useful even now as we can see in modern politics as waves of armies wash back and forth over the planet for God and Allah and yet, somehow, always where there is oil.
