But, then, doesn’t this somehow violate Paul’s principle? That one cannot work and so obligate God?
This is where Paul’s principle (Rom 4:4) is important in relation to Paul’s teaching on grace. There is a difference between a grace relationship and a works relationship (in the sense that we have defined it).
In a works relationship, of the type Paul condemns, one is working so as to obligate God to repay oneself. This is not only fruitless, it is foolish. As if man could obligate God to do anything! It is an insult against the divine.
But in a grace relationship, one cries to God, “Abba, Father!” (Rom 8:15) in a “spirit of sonship” (8:14).
We often miss the importance of the familial import of these verses. Here is the essential difference between the two relationships. In the works relationship, one is engaging with God in a legalistic relationship, trying to obligate God by one’s work. In the grace relationship one becomes a member of God’s family and approaches him as an adopted son.
Picture how a father acts in regards to his child. A father is not harsh, he is loving. And picture a son-- he does not approach his father as an unloving master, but as benevolent. Above all, the son tries, no matter how inadequately, to please his father.
Now, this is no surprise. Speaking of faith, the letter to the Hebrews proclaims:
But without faith it is impossible to please him, for anyone who approaches God must believe that he exists and that he rewards those who seek him (Heb 11:6).
This occurs after the famous definition of faith offered just verses before (11:1). Now, it is peculiar to note the interplay between faith and works here. Why is it impossible to please God without faith?
In the first, one must believe God exists. How can one please God if one doesn’t believe God exists? Who would even try?
In the second, the person of faith must believe God ‘rewards those who seek him.’ Wouldn’t it be pointless to seek God if we didn’t think that he would reward us for doing so?
And so this is exactly the position of the adopted son-- he believes that God the father exists, and tries to please him by his works.
In the strict sense-- that of commutative justice-- he can never please God the Father, for he can never obligate Him. But, coming to God in faith, in the system of grace, God will look upon him and his works, and he will benevolently bestow upon him rewards-- not because of strict justice, but out of the overabundance of His love.
Hence Augustine’s beautiful passage, adopted by the Council of Trent and used in the recent Catechism:
You are glorified in the assembly of your Holy Ones, for in crowning their merits you are crowning your own gifts.
Truly the mystery of salvation is a mystery of God’s great love and benevolence.
And so, the James passage-- was Abraham justified by faith or works?
It’s a false dilemma really. He was justified by faith *and *works.
Put in this light, James’s comments on justification are commonsense, for when we come to God in a relationship of grace, believing fervently that he exists and will reward us, it is no mystery that we are, “justified by works” as James attests, and further, it is no mystery how faith is then related to this process, “active along with” the works, because one must come to God believing that He exists and that he will reward us (what Hebrews calls faith). Nevertheless, they are two seperate realities, as James attests, being, “active along with” each other, and not some monstrous amalgam of, “saving faith,” which is not Biblical.
Justification, properly understood, is not merely a one time event, as El_camino pointed out. Scripture says Abraham was justified on three different events. Abraham increased ever in justification before our Lord by walking in faith and doing good.