Where does strife originate? What is the spark that causes interpersonal conflict to flare up? The Bible tells us the answer in James 4:1.
Conflict among us is the result of conflict within us.
Fighting among members of a group is a result of the war going on inside the individual members of that group. It is interesting that James uses the word ‘fights’ to describe what happens between two people, and uses the word ‘war’ to describe what happens inside one person. What happens on a group level is a small indication of what is going on within a person.