James 1, To the Diaspora
James' letter is specifically addressed to the 12 Tribes in the dispersion. Thus we (and he) may assume that the recipients are familiar with the TANAK. The letter has been called the proverbs of the New Testament, since the things it says can generally be found in slightly different form in Proverbs. Because Proverbs was written over 1000 years earlier than James, it is useful to regard James as a cultural and linguistic update.
James 2, Faith and Works
Some have trouble reconciling James with Paul's emphasis on grace. There is really no conflict. James is emphasizing that a faith which does not translate into action is of no use. In other words, it would not meet Paul's definition of faith.
James 3-4, Taming the Tongue
The tongue reveals the contents of the heart. In Scripture, God does not have a high opinion of man's heart. Accordingly James counsels keeping the tongue under control to avoid being consumed by the fires it can start.
James 4-5, Corroded Gold and Silver
At the end of the letter, James returns to the theme that great wealth is dangerous. Here he speaks against the one who has accumulated wealth by oppression, withholding the wages of those who labor in his fields. The letter concludes with a call to prayer and helping one another stay on the path.