In response to a question on Facebook, after I shared this article from Catholic Answers.
I might say that “faith plus works” can be a valid but misleading generalization — but not “grace plus works” (even though the article does clumsily put those side by side). Catholics do (and the Council of Trent did) fully affirm that salvation is by grace alone. Because everything is grace, even the works we do, since it is only by grace that we can work at all or even will to do good (Philippians 2:13, John 15:4). Even in that case (“faith plus works”), we are not saying that “works save us,” and in no sense do we mean works can “earn” salvation, or that anything must be added to the cross of Christ — which is why I generally disagree with the characterization “faith plus works.”
Catholics fully affirm that our initial justification — our initial rebirth in Christ — is entirely by faith alone through grace; it cannot be earned or deserved by anything we do or are. Since Protestants tend to compress the whole salvation experience into that initial justification, it’s easy to get the wrong idea when Catholics say that anything more (and “works” at that!) is required. But Catholics understand salvation as an ongoing process (so does Scripture: e.g. Philippians 1:6, 2:12–13, etc.), and roll into a part of “justification” what Protestants call “sanctification,” the ongoing process of being converted and conformed to Christ. And that — and most Protestants would agree — is wrought by “faith working in love” (Galatians 5:6, James 2:24).
Salvation is more than just being once forgiven; it’s being healed, renewed, and transformed by the love and grace of God. And God has designed to make us participants in that life of grace; we are not just passive recipients, but we receive that grace and bear fruit (John 15:1–4). Protestants say that good works are a fruit of grace, and Catholics agree. And just as Protestants say that a Christian who isn’t bearing any fruit possibly isn’t really “saved,” Catholics would likewise agree — only we would say that bearing that fruit is part of the ongoing process of being saved, being renewed and transformed in His image — which begins when we first receive His grace, and ends when we see Him face to face.