“The words, ‘It was credited to him’ were not written for him alone,
but also for us, to whom God will credit righteousness–for us who believe
in him who raised Jesus our Lord from the dead.” Romans 4: 23-24 NIV
Romans is unique among the New Testament epistles in that Paul is mainly concerned with presenting New Covenant theology.
After making the case in Romans 1-3, that the righteousness of the saints is by faith in Christ alone, Paul, shows us the example of the patriarch, Abraham in chapter 4. In verse 3, (quoting to Genesis 15:6), Paul writes: “Abraham believed God, and it was credited to him as righteousness.” This was nearly 2,000 years before Jesus died for his sins and some 450 years before there was an old covenant. Abraham was living by faith as a New Covenant believer!
Paul (vs. 7,8) mentions King David briefly saying the same thing in Psalm 32: 1-2, “Blessed are they whose transgressions are forgiven, whose sins are covered. Blessed is the man whose sin the Lord will never count against him.” Roughly 1,000 before Christ, David explained the assurance of salvation — knowing that his sin would never be counted against him. That’s living by faith.
We’re all familiar with the famous verse in Romans 1: 17, “The righteous will live by faith.” That didn’t originate with Paul. He actually quoted here from the Old Testament book of Habakkuk Ch. 2:4. I’m reminded of the man Job, who very likely lived around the time of Abraham. In Job 19:25 Job declares, “I know that my Redeemer lives.”
Of course, Hebrews 11 is a “Hall of Fame” of the faithful who lived before the time of Christ. Verse 13 says, “All these people were still living by faith when they died.” They were living as New Covenant believers. Even though they were looking forward to when the Redeemer would come, and we are looking back, it has never been any different: The righteous live by faith. They always have!