Called a Friend of God
James 2:23 (ESV) … “and the Scripture was fulfilled that says, “Abraham believed God, and it was counted to him as righteousness”—and he was called a friend of God.”
Unique in James, we have in this verse a reference to the fulfillment of Scripture. This connection arises from the relation between the statement from Gen 15:6 that Abraham’s faith was reckoned as his righteousness by God and the actual birth of his son Isaac twenty-five years later. This is part of a shorthand review of Abraham’s faith in God: a glancing back to the beginning of Abraham’s walk of faith with God and God’s acceptance of him, the waiting for the promised child, the evidence of his friendship with God and—from the previous verse—the completion of his faith in offering up Isaac. The fulfillment text is quoted by Paul as well in Rom 4:3, which frames an entire context in order to convey much more teaching on the significance of Abraham. It includes the statement, “Against all hope, Abraham in hope believed and so became the father of many nations” (Rom 4:18).
Of course the difference of perspective between Paul and James rests in this: James looked to the Abraham story to show how genuine faith operates; Paul looked to the Abraham story to show how God is predisposed to forgive sinners. At the heart of the difference between the “works” James was advocating and those that Paul was combatting by relativizing the act of circumcision (Rom 4:10–12) were the conditions under which righteousness was “credited” to Abraham. Abraham was justified by trusting the promise of God, not his act of circumcision. The lack of any reference to circumcision in James is highly significant.
Circumcision signified for Paul the kind of relation to activities whereby his fellow countrymen justified themselves, indeed, found resources for religious boasting (4:2). Paul was vehement in his rejection of this kind of observance of the law (4:13), which damaged the divine/human relation in faith. Abraham was God’s example of how boasting in the command of God and act of man had missed what was intended for faith, that “the promise comes by faith” (4:16). Thus close inspection of the ways in which Abraham’s story illustrates the messages of James and Paul differently helps us allow their distinctive messages to be heard.
James summed up what he had to say about the example of Abraham by citing a choice title for him within the Old Testament: “God’s friend” (cf. 2 Chr 20:7; Isa 41:8). Abraham had been drawn into God’s deliberations about how he would judge the sinful cities of the plain. Abraham had asked his divine Visitor about punishing the righteous along with the unrighteous: “Will not the Judge of all the earth do right?” (Gen 18:25). In the covenant conversation between Abraham and the Lord, the Lord included him in every way. Abraham could not have been but amazed and wholly satisfied that God had heard his plea and engaged his questions. God had made Abraham his friend. Abraham as friend of God became the true exemplar of faith, for to be a believer one must commune with God in friendship. As James later argued, believers must renounce the pride that typifies “friendship with the world” (4:4–5) and humbly accept the will of God in order to enjoy friendship with God. 
 Richardson, K. A. (1997). James (Vol. 36, pp. 140–141). Nashville: Broadman & Holman Publishers.