This excerpt from a previous book review post of a few days ago is re-quoted below. It is interesting that while, on the whole, there is probably no practical convergence between Catholics and Lutherans on justification, due to many factors not addressed here, that a Catholic theologian, who is also a Roman pontiff, might "get away" with advancing the scriptural understanding of the relationship between faith and works and allowing Scripture to interpret Scripture (ie, both Paul and John, not just Paul).
". . .
"Rowland points out that Ratzinger is ever ready to come to agreement with various controversial positions once it is clear that what is at stake is compatible with the faith. Take the classic issue with Lutherans about faith and works. "Ratzinger agreed that while Christians are obliged to do good works, justification and final judgment remain God's gracious acts. The actual wording of the key sentence of the declaration is as follows: 'By grace alone, in faith in Christ's saving work and not because of any merit on our part, we are accepted by God and receive the Holy Spirit, who renews our hearts while equipping us and calling us to do good works' (139). [emphasis mine]
"This happy formula at the same time avoids the issue of Pelagianism, that is, the claim that we save ourselves by our own powers. Ratzinger retains the Pauline and Johnanine teachings about the first necessity of grace in our salvation. One might say this happy result is due both to good will and to careful thinking that clearly understands the whole issue in its principles and in its development.
. . ."
[Ironically, to most Catholics this is probably a non-issue anymore while to many Lutherans, even if they may concede that the above formula is scriptural would pass over this commonality and quickly point to any number of other areas of disagreement, raising the question if justification really is "the" issue after all.]