Barnes New Testament Notes

Verse 25. Likewise also was not Rahab the harlot justified by works? In the same sense in which Abraham was, as explained above -- showing by her act that her faith was genuine, and that it was not a mere cold and speculative assent to the truths of religion. Her act showed that she truly believed God. If that act had not been performed, the fact would have shown that her faith was not genuine, and she could not have been justified. God saw her faith as it was; he saw that it would produce acts of obedience, and he accepted her as righteous. The act which she performed was the public manifestation of her faith, the evidence that she was justified. See Barnes on "Heb 11:31"

for a full explanation of the case of Rahab. It may be observed here, that we are not to suppose that everything in the life and character of this woman is commended. She is commended for her faith, and for the fair expression of it; a faith which, as it induced her to receive the messengers of the true God, and to send them forth in peace, and as it led her to identify herself with the people of God, was also influential, we have every reason to suppose, in inducing her to abandon her former course of life. When we commend the faith of a man who has been a profane swearer, or an adulterer, or a robber, or a drunkard, we do not commend his former life, or give a sanction to it. We commend that which has induced him to abandon his evil course, and to turn to the ways of righteousness. The more evil his former course has been, the more wonderful, and the more worthy of commendation, is that faith by which he is reformed and saved.

{a} "Rahab the harlot justified by works" Jos 2:1