So also faith by itself, if it does not have works, is dead. (ESV)
In the previous verses James used an illustration of a person offering to make a hungry person to be filled with food, yet never actually giving them anything. Their words of compassion were completely phony because they were not accompanied by the actual food that was needed. True compassion is followed by action.
"So also, . . ." In the same way that compassion without action is phony, faith without works is phony as well. It is important that we recognize that it is not our works that save us, but our works accompany genuine faith. As Paul makes clear in Ephesians 2:8-10 we are not saved by our works, but we are saved UNTO good works. The works are evidenced of a genuine faith.
 For by grace you have been saved through faith. And this is not your own doing; it is the gift of God,  not a result of works, so that no one may boast.  For we are his workmanship, created in Christ Jesus for good works, which God prepared beforehand, that we should walk in them. (ESV)
There are two things that we should look for when one claims saving faith in God. One, are they claiming to have faith, but have given evidence of no works? That is not a Christian, that is a phony. Two, are they doing all kinds of works, but they have never placed their faith in the finished work of Jesus Christ, on the cross? If so, they are a phony.
When you walk into any church you will find that most people will claim to be Christians. Not all who make that claim are telling the truth. This is why it is so important to emphasize what James is talking about here. We must place our faith in Christ. If we have genuinely done that we will evidence it by doing the good works that God prepared in advance for us to do.
Is your faith real? Have you placed your faith in the finished work of Jesus Christ for your salvation? If so, what evidence would the world see of your faith in the works that you are doing?