“Abraham believed God and it was counted unto him for righteousness” (Rom. 4:3).
Has it ever occurred to you that the most loved, the most honored, the most respected person of all history is — not Christ, but Abraham. Christ ought to be most loved, honored and respected, but Abraham is. Besides the millions of professing Christians there are untold millions of Jews and Mohammedans who speak with reverance of “our father Abraham.”
Clearly this is why God used this man to show how to be saved and justified before a holy God. As Paul is God’s great example of grace, so Abraham is God’s great example of faith — saving faith.
“If Abraham were justified by works,” says Rom. 4:2, he has something to boast about — but not before God, who sees and knows all. But Abraham was justified. How? “What saith the Scripture? Abraham believed God and it was counted to him for righteousness” (Ver. 3).
God, of course, had planned salvation through the redemptive work of Christ and has always saved anyone who simply trusts Him and takes Him at His Word. Since Abraham, of course, more of God’s Word has been revealed and we know the details of Christ’s death for sinners. If we now take God at His Word and simply trust Christ as Savior we are completely justified, for salvation is not; cannot be, by works:
“But to him that worketh not but believeth on Him that justifieth the ungodly, his faith is counted for righteousness” (Rom. 4:5).
“…through this Man is preached unto you the forgiveness of sins, and by Him all that believe are justified from all things, from which ye could not be justified by the law of Moses” (Acts 13:38,39). source