“And he believed in the LORD; and He counted it to him for Righteousness,” (Genesis 15:6)
There are those who interpret this declaration to mean that faith was the basis of Abraham being justified, and that because he believed in the LORD, therefore God justified him. While this may appear to be what the Scripture is saying, nothing could be further from the truth.
1.) Faith is never said to be the reason for God justifying sinners. The apostle Paul in Romans 4:1-2 plainly taught that if there were anything in Abraham that were the cause of God justifying him, then Abraham might have reason to boast, BUT NOT BEFORE GOD!
2.) Faith is the fruit of God’s Spirit revealing Christ in them as the One by whom He justifies sinners. The original Scripture in Genesis 15:6 states that Abraham ‘believed IN the LORD.’ The apostle Paul in answer to ‘what saith the Scripture’ affirms, ‘Abraham believed God.’ No sinner could ever believe God, apart from the Spirit of God being in them, 1 Corinthians 2:12. More precisely, the God in Whom Abraham believed was no other than God in the flesh, the LORD Jesus Christ who would come as the Promised Seed, to earn and establish a righteousness equal to that of God, and thereby Abraham would be then and there justified (declared righteous).
The LORD Jesus said to the Pharisees who trusted that they were righteous in themselves, “Your father Abraham rejoiced to see my day: and he saw it, and was glad,” John 8:56. While some argue that the Spirit of Christ never indwelt any before Pentecost, the Scripture states just the opposite in 1 Peter 1:11, “Searching what, or what manner of time the Spirit of Christ which was in them did signify, when it testified before hand the sufferings of Christ, and the glory that should follow.”
3.) Faith was accredited to Abraham to look to the righteousness that Christ would earn and establish and God the Father impute upon completion of His work at the cross. Whether in the Old or the New Testament, God has always saved sinners the same way. Those He purposed to save from eternity, He sent His Son to earn and establish His righteousness, by fulfilling law and justice for them and thereby declare them righteous because of the completed work of the LORD Jesus at the cross. Before the cross, the Scripture reveals that faith was credited (accounted) to God’s children for (unto) righteousness (that righteousness that the LORD Jesus was yet to work out, but faith accorded that rested in what He was yet to accomplish. The writer to the Hebrews wrote that ‘these all, having obtained a good report through faith, RECEIVED NOT THE PROMISE: Godhaving provided some better thing for us, that they without us should not be made perfect,” (Hebrews 11:39-40).
Where, when, and how God justifies sinners is the same, whether for Old Testament sinners or since the cross. Hebrews 9:15 reveals, ‘And for this cause He is the Mediator of the New Testament, that by means of death, for the redemption of the transgressions that were under the First Testament, they which are called might receive the promise of eternal inheritance.’
The only way that sinners have ever been justified by God is in, through and by the LORD Jesus at the cross. Romans 3:24- “Being justified freely by His Grace through the redemption that is in Christ Jesus:”
Faith is the gift of God to those sinners that He purposed to save from eternity, that they might rest in Christ and His finished work ALONE, and not put any confidence in any works of the flesh, Philippians 3:3.