Which is interesting, because you would think the 'correct' way of life would be the one that causes the least human suffering.

The gears behind the mechanism of morality are that whatever you do reduces the amount human suffering, mentally and physically, and that by being 'moral' you are ceasing to persecute, punish or harm without motivation.

The way of life that should 'win' is the one that causes the least human suffering and mental anguish in times of peace.
If the two sides could get past seeing it as a war of religion, and instead see it as a war of how to live and leave the issue of god out of it, more discussion and less fighting could be achieved.