James previously spoke of faith || works. With his pattern ABBA (A=wisdom, B=works) he identifies the works the wise man is to do: good conversation. He is making an analogy of Faith is to wisdom as works is to good conversation.
"I will show you my wisdom by good conversation of knowledge."
The point is subtle. Works do not boast of faith, as the knowledge is not boastful as it demonstrates wisdom. Knowledge and works display the wisdom and faith, with meekness.