James is the earliest book written in the New Testament. He begins by helping the Jewish believers to properly understand and react to trails that would come into their lives. All of us face trials each and every day; and knowing what God is accomplishing by allowing trials in the believers is very helpful. 

Paul deals with a subject about which every one must constantly be on guard. We must all watch what is being allowed to enter our minds. There is no easier way for us to lose our peace than to have unguarded ideas influence our thinking. Does the peace of God reside in your heart? 

Paul is dealing with our joy and warning about those areas that can steal our joy. We must watch for circumstances, people, things and in the last chapter worry. Paul will describe how we must find our peace and trust in Christ. Satan wants to cause worry to rob of us of the tranquility we can have in Christ.