Genesis 15:6-7

Moses did not reveal exactly what Abram believed (confidently trusted, relied upon) for which God reckoned him righteous. In Hebrew the conjunction waw with the imperfect tense verb following indicates consecutive action and best translates as "Then." When waw occurs with the perfect tense verb following, as we have here, it indicates disjunctive action and could read, "Now Abram had believed . . ." (cf. Genesis 1:2). God justified Abram (i.e., declared him righteous) because of his faith. Abram’s normal response to God’s words to him was to believe them. Abram had trusted the person of God previously, but he evidently had not realized that God would give him an heir from his own body (Genesis 15:4). Now he accepted this promise of God also (cf. Romans 4:3; Galatians 3:6; James 2:23). Perhaps he believed the "counting" promises of Genesis 13:16 and Genesis 15:4-5 regarding numerous descendants, and the result was that the Lord "counted" his faith as righteousness. [Note: Mathews, Genesis 11:27-50:26, p. 167.]

"In the middle of this chapter occurs what is perhaps the most important verse in the entire Bible: Genesis 15:6. In it, the doctrine of justification by faith is set forth for the first time. This is the first verse in the Bible explicitly to speak of (1) ’faith,’ (2) ’righteousness,’ and (3) ’justification.’" [Note: Boice, 2:98.]

Trust in God’s promise is what results in justification in any age. The promises of God (content of faith) vary, but the object of faith does not. It is always God. [Note: See Charles C. Ryrie, Dispensationalism Today, pp. 110-31; or idem, Dispensationalism, pp. 105-22.] Technically Abram trusted in a Person and hoped in a promise. To justify someone means to declare that person righteous, not to make him or her righteous (cf. Deuteronomy 25:1). Justification expresses a legal verdict.

Moses probably recorded Abram’s faith here because it was foundational for making the Abrahamic Covenant. God made this covenant with a man who believed Him.

James 2:21 suggests that Abram was justified when he offered Isaac (ch. 22). James meant that Abram’s work of willingly offering Isaac justified him (i.e., declared him righteous). His work manifested his righteous condition. In Genesis 15 God declared Abram righteous, but in Genesis 22 Abram’s works declared (testified) that he was righteous.

"In the sacrifice of Isaac was shown the full meaning of the word (Genesis 15:6) spoken 30 . . . years before in commendation of Abraham’s belief in the promise of a child. . . . It was the willing surrender of the child of promise, ’accounting that God was able to raise him up from the dead,’ which fully proved his faith." [Note: Joseph Mayor, The Epistle of Saint James, p. 104. Cf. Zane Hodges, The Gospel Under Siege, pp. 28-31.]