Spiritual Warfare

I need some help in understanding this concept of spiritual warfare.

First of all -- Is this a battle between spirits, for spirits, or by spirits?
And secondly -- How has this spiritual battle often turned into actual physical violence between human beings?

It seems a bit sci-fi-ish to talk about a battle between the spirit realm and the physical realm, but that is the image that I always come up with when confronted with the topic of spiritual warfare. 
Do we physical beings sit this one out while waiting for our souls to be divided or won by powerful, eternal beings (angels and demons) of the spiritual realm?

Or are human beings active participants in this battle, winning and losing souls for our side?
How do we do that? 
Doesn't killing the infidels put them permanently on the other side?

From a simple human perspective I am having a really difficult time reconciling that we must do battle for the powerful spirit forces that are engaged in some epic battle for control of the earth and all of its resources (both people and riches).
It sounds an awful lot like our own wars -- rich and powerful people using the lower classes to do battle so that they have more stuff and control more people.

Could it be that spiritual warfare is as much bullshit as actual warfare?
Could it be that the idea of this great spiritual battle is just another lie told by religious leaders to bring followers under control?
Why would a god of any realm need to use mere humans to do battle?
Or are we just collateral damage; a resource to be won or lost in their epic battle?

Or maybe we are just a vile and violent people that will use anyone and any means to take from others.
What if there is no spiritual war?
What if there is no battle for the souls of humanity?
What if the battle for religious control is just a fight for control?
What if we are mere pawns in a chess game of powerful people?

Can we decide not to participate?
Can we decide not to hate?
Can we decide that violence isn't the way?
Can we decide that we don't need to be in control of other people, or nations, or religions?

I hope you didn't come here today seeking answers.
All I have are questions.

John