Doesn't James 2:24 teach that we are justified by works and not by faith alone?
The justification used in James is a different justification used in Romans 4:5, 5:1, and other places by Paul. When James used "justified," it could also be understood as "vindication." Here the works complete the faith. They should be the products of a genuine, vital faith. That has more of a "proving" or "showing" sense to oneself and to others (cf. the context, particularly James 2:18). God already saw the heart of Abraham when he believed God had told him that he would have a son, and then God counted Abraham as righteous (Genesis 15:6). This was way before the event that James used to be an example of the work that "vindicates" one's faith (Genesis 22). There is a difference between phony faith or mere intellectual faith on the one hand and genuine or transformational faith that obviously and naturally produces good works on the other. Sheep grow wool and bleat because they are sheep, not because they want to become sheep. So, as Calvin said, "faith alone saves, but the faith that saves is never alone."
This is all perfectly consistent with Paul's use of justification. His use means being declared righteous even though we are miserable sinners by nature, and for him, this once for all action is produced via a genuine faith apart from any works. Nonetheless, even Paul acknowledged that this genuine faith is, in James' usage, "justified" or has its "vindication" in good works (e.g., Galatians 5:6 and Ephesians 2:10).
R. M. Sivulka