The purpose of James was to serve as a general letter to “the twelve tribes” (aka Israel). The letter tries to encourage the oppressed, chastise internal strife, criticize Christian sin, correct misconceptions concerning works, and remind people that the end was near.
For the sake of this writing, it is assumed that the author “James” is the same James who was the brother of Jesus (and early in Acts becomes the leader of the church). The purpose, authority and theology fit.
James was writing to established Jewish churches (he uses the word “synagogue”). They were mostly poor, and a large section of James is devoted to their relations to the “rich”. James uses an “us versus them” mentality when talking about the rich. The “rich” seem to be the primary cause of the oppression of the Christians, and this was through court proceedings and fraudulent wages.
In chapter 1, James addresses his most pressing concern. People were claiming that God was making them do evil. They were justifying their evil through fatalism! James explains that no one is forced to sin, and each person is responsible for their own actions. James uses a large part of his letter to combat the notion that sin is allowable or justifiable, even if an individual has faith.
Connected in James’ mind was “sin” and “a lack of good works”. James equates sinning with not doing good works (Jas 4:17 Therefore, to him who knows to do good and does not do it, to him it is sin). The audience of James seems to have been lacking in good works. James reminds them to visit widows and orphans, and explains that keeping themselves “unspotted” from the world (a very Jewish concept) is the mark of pure religion. He also talks about how they treat people, noting that everyone is equal. If Christians show favoritism, they are sinning (Jas 2:9 but if you show partiality, you commit sin…).
On top of this, it appears that there was plenty of internal strife that James had to address. In chapter 1, he talks about untamed tongues, recapped in chapter 3. In chapter 4, James addresses “desire”, “murder”, and “war”. In chapter 5, he reminds Christians that they might be condemned by God if they grumble against each other. Somewhere in the Church something bad was happening.
James encourages them to repent, and reminds them that the end of the world is near. Interwoven throughout James is his apocalyptism.
The entire context of James was to prepare believers for an imminent return of the Kingdom of God. To James “the judge was at the door”, “people should not say what they were doing in a month”, “the coming of the Lord was nigh”. James echoes Jesus’ teachings that judgment would be soon and would be harsh. God would use his army of angels (“the Sabaoth”) to kill the unrighteous (“the day of slaughter”). He uses the rich oppressors as an example, and warns Christians to watch what they do and say lest they be judged in the same fashion.
When James talked about salvation, justification, righteousness, faith, and works, it is in this context. James is not preparing his followers for interpersonal relationships; he is preparing them for the apocalypse. James echoes Jesus’ ministry:
Compare: “Repent, for the kingdom of heaven is at hand.” (Mat 4:17) and “Establish your hearts, for the coming of the Lord is at hand.” (Jas 5:8)
In James, we find nothing resembling common Christian creeds. Nothing is said about the death of Christ, his blood, or his resurrection. Nothing describes Jesus’ role in the mechanics of salvation or attaining righteousness. It is just assumed that faith in the coming Kingdom, good works (and not sinning) was sufficient to avert judgment. Combined with an exclusive focus on the Jews, this points to an early date for the writing of James (perhaps before Acts 15).
James ends his letter, not with a farewell, but by saying that conversion from sin was the primary goal. In fact, converting one sinner from their sins covered a multitude of the converter’s sins:
Jas 5:20 let him know that he who turns a sinner from the error of his way will save a soul from death and cover a multitude of sins.