One of the most prominent themes in James is human speech. While James mentioned the importance of controlling our tongues in James 1:19 and 1:26, he dedicated most of James 3 to the power of speech for good or for evil. He also pointed us to the help we need to harness our speech for good.
As the second Adam and the faithful Israel, Jesus resisted temptation and so can help us when we are tempted.
While the Old Testament is still valid, we also have the message of the one who was raised from the dead.
The first psalm describes the two ways to live and their results.