For as the body without the spirit is dead, so faith without works is dead also. For as the body without the spirit is dead - There can be no more a genuine faith without good works, than there can be a living human body without a soul.
We shall never find a series of disinterested godly living without true faith. And we shall never find true faith without such a life. We may see works of apparent benevolence without faith; their principle is ostentation; and, as long as they can have the reward (human applause) which they seek, they may be continued. And yet the experience of all mankind shows how short-lived such works are; they want both principle and spring; they endure for a time, but soon wither away. Where true faith is, there is God; his Spirit gives life, and his love affords motives to righteous actions. The use of any Divine principle leads to its increase. The more a man exercises faith in Christ, the more he is enabled to believe; the more he believes, the more he receives; and the more he receives, the more able he is to work for God. Obedience is his delight, because love to God and man is the element in which his soul lives. Reader, thou professest to believe; show thy faith, both to God and man, by a life conformed to the royal law, which ever gives liberty and confers dignity.
"Some persons, known to St. James, must have taught that men are justified by merely believing in the one true God; or he would not have taken such pains to confute it. Crediting the unity of the Godhead, and the doctrine of a future state, was that faith through which both the Jews in St. James' time and the Mohammedans of the present day expect justification. St. James, in denying this faith to be of avail, if unaccompanied with good works, has said nothing more than what St. Paul has said, in other words, Romans 2, where he combats the same Jewish error, and asserts that not the hearers but the doers of the law will be justified, and that a knowledge of God's will, without the performance of it, serves only to increase our condemnation." - Michaelis.
Commentary on the Bible, by Adam Clarke [1831].