What does James 4:2 mean?
James continues making the case to his Christian readers that they are living according to the world's wisdom. They are not trusting God to provide while serving others, which is the wisdom of heaven.Driven by bitter envy to get what they want, and a deep ambition to serve themselves, James's readers continue to kill, quarrel, and fight. This is not necessarily a direct accusation of murder or mayhem. A major point of James's words are the effects which worldly wisdom leads to. We have no way of knowing how violent this conflict had become. Had someone actually been murdered, or was James equating their hatred of each other to murder? Perhaps, but regardless of the severity, it's clear these religious people are off track.
At the heart of the problems is their response to not getting what they want out of life. In those moments when we realize that what we want is still out of our grasp, we always have a choice. The world's wisdom tells us to sacrifice everything to get what we want, including the welfare of others. The world will tell us to fight, to scratch, to wound, if that's what it takes. Driven by envy for what they want, James's readers are frustrated when they keep coming up empty. So they fight.
James identifies their root problem: These believers in God refused to trust Him to provide what they needed. They refused to even ask God for what they wanted. God might say no, after all. They were not willing to trust that if God would not give it to them, it was something they could live without for now. They would rather hurt someone else in attempting to provide it for themselves.