Through faith in Christ, therefore, Christ's righteousness becomes our righteousness and all that he has becomes ours; rather, he himself becomes ours. Therefore the Apostle calls it "the righteousness of God" in Rom. 1:17: For in the gospel "the righteousness of god is revealed...; as it is written, "the righteous shall live by his faith.'" Finally, in the same epistle, chapter 3:28, such a faith is called "righteousness of God": "We hold that man is justified by faith." This is an infinite righteousness, and one that swallows up all sins in a moment, for it is impossible that sin should exist in Christ. On the contrary, he who trusts in Christ exists in Christ; he is one with Christ, having the same righteousness as he. It is therefore impossible that sin should remain in him. This righteousness is primary; it is the basis, the cause, the source of all our own actual righteousness. For this is the righteousness given in place of the original righteousness lost in Adam. It accomplishes the same as that original righteousness would have accomplished; rather, it accomplishes more.
- Martin Luther, Two Kinds of Righteousness, in Martin Luther's Basic Theological Writings, ed. Timothy Lull (Minneapolis: Fortress Press, 1989).