The Bible teaches that true, authentic faith demands abandoning one’s own life in order to wholeheartedly follow Christ. Paul uses Abraham as an illustration of this kind of faith.
One of Paul’s primary points in Romans 4 is that true, authentic faith is not merely intellectual assent to the facts of the gospel. Those facts are necessary, but the facts alone do not save anyone. Rather, you have to have knowledge of the gospel, you have to be convinced that that knowledge is in fact the truth, and you have to trust in Jesus Christ alone for salvation.
The Bible teaches that justifying faith is deeply rooted in the character of God. In fact, it is God alone who not only has the power to give spiritual life to spiritually dead sinners, but He also desires to do so. His merciful and gracious character towards sinners is displayed through the person and work His Son, Jesus Christ.
In Romans 4 Paul uses the Old Testament character, Abraham, as an illustration of what it means to be justified by faith before God: Abraham believed God and it was credited to him as righteousness.
The Bible often connects justification, or salvation, with the grace of God—that attribute of God by which He desires to be gracious to those people who deserve the exact opposite. As he uses Abraham as an illustration of true, saving faith in Romans chapter 4, Paul says that a mark or quality of that faith is that it is a gift of God’s grace.
In Romans 4 Paul uses Abraham as an illustration, or portrait, of true, saving faith—the fact that Abraham believed the promises of God and was justified by faith alone. God’s gracious interaction with Abraham is the template for justification by grace alone.
In Romans 4 Paul uses an Old Testament character, Abraham, to illustrate several qualities that are true regarding the great doctrine of justification. One of those qualities is that even though we as Christians have weaknesses, true saving faith focuses on God’s promises and on God’s power to keep us saved. This was true of Abraham and it is true of every Christian.
In Romans 4 Paul uses a financial term to describe that amazing transaction that takes place in the important doctrine of justification. That term is “credit.” It is a legal decision of God as Judge in which He credits the believing sinner’s sins to Christ on the cross, and then He credits to the sinner the merits of Christ’s perfect life—His righteousness. This entire transaction is born out of God’s grace alone and it is of faith alone.