Gen 15:6

15:6 This verse provides the early core doctrine of justification by faith, not by works (Gal. 3:6–14). Abraham believed the promise of the birth of an heir from the dead (Rom. 4:17–21; Heb. 11:11, 12), and God counted Abraham to be righteous, to be meeting His covenant demand. Abraham’s justification by faith is a model of our faith in the resurrection of Jesus Christ, God’s sacrifice for sin, and God’s crediting His righteousness to us by faith (Rom. 4:22–25).

believed. Abraham is father of all who believe (Rom. 4:11), and all who believe are children of Abraham (Gal. 3:7).

righteousness. See 6:9 and note; Heb. 11:6–12.