This is vital because we find ourselves living in a culture that is coming apart at the seams because each individual wants to execute his desires. James tells us what happens when individuals begin to do this.
His basic question to the Christian is, "Are we going to submit to God or to our desires for pleasure?" Pleasure here does not mean "fun," as when one goes to an amusement park. James is talking about the desire that normally arises within an individual, who must make the choice of whether or not he is going to follow through and gratify himself by fulfilling that desire. So pleasure here means "that which gratifies."
He is saying to us that, if we seek our desires, then we had better understand that life will be filled with conflict. Why? Because everybody else is doing the same thing. Their desires are likely different from ours, and so our desires runs headlong into their desires, producing arguments, struggle, strife, and war over whose desire is going to be fulfilled. When people do what is right in their own eyes, rather than submit to the central authority, desires will crash into each other, creating conflict. It does not matter whether that central authority is the family, the culture, or God's Word!
This is happening constantly, but God has a solution. It is not easy. The solution is that each son of God bears the responsibility to govern himself, by faith, within the framework of His laws, His principles, His traditions, and the examples that He gives in His Word. We have to submit to these things.
John 8:32 declares that the truth sets us free, but it will never set anyone free unless it is submitted to. Truth is good only as it is used, so a person must submit to it. Inevitably, differences will arise on what things should be done or how they should be done. But God has a way of resolving these problems if we will submit and not succumb to impatience—if we do not force our will and thus force conflict.