James had no doubt observed the incredible power of the tongue to stir up the inclinations of the whole body and of all of its parts – our own body as well as that of others. Have you observed this? It is perhaps the last bodily part to submit to goodness and rightness. No one can tame it, James said, and indeed that is right. Physical violence nearly always is introduced by verbal violence.
From the book "Renovation of the Heart: Putting on the Character of Christ (Th1nk LifeChange)"