What causes fights and quarrels in our lives? You might promptly turn in your Bible to the opening lines of James 4 for the answer:
What causes quarrels and what causes fights among you? Is it not this, that your passions are at war within you? You desire and do not have, so you murder. You covet and cannot obtain, so you fight and quarrel. You do not have, because you do not ask. You ask and do not receive, because you ask wrongly, to spend it on your passions. (James 4:1–3)
There it is.
What causes our fights and quarrels?
We want. We are want-ers. We are driven by desires. And want-ers, driven by unchecked desires, find themselves in a lot of fights — some bloody fights, but mostly unseen fights, non-physical fights, the kind of internal loathing towards others, a pot of boiling acid that simmers under the surface and only rarely bubbles up and bursts out in verbal disdain.