John Calvin Commentary James 2:25

"And in like manner was not also Rahab the harlot justified by works, in that she received the messengers, and sent them out another way?" — James 2:25 (ASV)

Likewise also was not Rahab. It seems strange that he connected together those who were so unlike. Why did he not rather choose someone from so large a number of illustrious fathers and join him to Abraham? Why did he prefer a harlot to all others?

He intentionally put together two persons so different in their character, in order more clearly to show that no one, whatever their condition, nation, or class in society, has ever been counted righteous without good works. He had named the patriarch, by far the most eminent of all; he now includes, in the person of a harlot, all those who, being foreigners, were joined to the Church. Whoever, then, seeks to be counted righteous, though they may even be among the lowest, must yet show that they are such by good works.

James, according to his manner of speaking, declares that Rahab was justified by works; and the Sophists therefore conclude that we obtain righteousness by the merits of works. But we deny that the dispute here is concerning the mode of obtaining righteousness. We, indeed, allow that good works are required for righteousness; we only take away from them the power of conferring righteousness, because they cannot stand before the tribunal of God.