The General Epistle of James, written by the brother of our Lord, provides ethical instruction for all Jewish people who have become Christians. It is clear and practical in its dealing with Christian behavior.

James 1

1:11 For the sun is no sooner risen with a burning heat, but it withereth the grass, and the flower thereof falleth, and the grace of the fashion of it perisheth: so also shall the rich man fade away in his ways.