Final answer:
James uses the illustrations of Abraham's willingness to sacrifice Isaac and Rahab's aid to the spies as Old Testament examples of faith evidenced by works, which is a part of Christian typology.
Step-by-step explanation:
James, in the context of Christian theology, uses Old Testament illustrations to demonstrate that faith is evidenced by works. One key illustration that James cites is the willingness of to sacrifice his son Isaac, which is a type of the sacrifice that God the Father would make of His own Son, Jesus Christ, on the cross. This act of Abraham is seen as a foreshadowing of Christ's sacrifice and signifies that faith must be accompanied by works—an indication of true belief. The second illustration that James uses is the story of Rahab the harlot, who by faith received the spies sent by Joshua and was spared from the destruction that befell the city of Jericho.
The concept of typology is key to understanding how Old Testament events were seen by early Christians as prefiguring or foreshadowing New Testament salvation narratives. These narratives, such as the mentioned stories of Abraham and Rahab, were often portrayed in Christian art and liturgy to emphasize the continuity and fulfillment of God's salvation plan through Christ.