The following is not the Protestant understanding of Grace
Merit
2010 Since the initiative belongs to God in the order of grace, no one can merit the initial grace of forgiveness and justification, at the beginning of conversion. Moved by the Holy Spirit and by charity, we can then merit for ourselves and for others the graces needed for our sanctification, for the increase of grace and charity, and for the attainment of eternal life. Even temporal goods like health and friendship can be merited in accordance with God's wisdom. These graces and goods are the object of Christian prayer. Prayer attends to the grace we need for meritorious actions.
2016 The children of our holy mother the Church rightly hope for the grace of final perseverance and the recompense of God their Father for the good works accomplished with his grace in communion with Jesus.70 Keeping the same rule of life, believers share the "blessed hope" of those whom the divine mercy gathers into the "holy city, the new Jerusalem, coming down out of heaven from God, prepared as a bride adorned for her husband."71(emphasis ours)
Catechism of the Catholic Church
Periodically some non-caucus Protestant topic is posted, usually about arminianism v double predestination or something of the kind. There is no urge that I'm aware of for me to come in and tear up the pea-patch and being up every beef I have with Protestantism, in its multifarious splendor.
But within a hundred or so posts from the beginning of a thread about Catholics teaching on and devotion to the Virgin here it all comes implicitly or explicitly, The Authority of Scripture v. tradition, merit v. grace, immaculate conception, at least one shot hurtling in the general direction of the doctrine of the Trinity. It's as though there's one thing Protestants can get back together on, Them Calflicks need to be STOPPED! We can't even let them articulate what they think, we've got to stop them.
And then there's the phenomenon of the line of arguments infinitely wide but one deep: We'll fire the Immaculate conception argument, then step down the line and fire the merit v. grace argument, and then down the line to the next controversy.
There are some physicians who kill babies born alive, and others who will amputate perfectly healthy limbs of people who will pay for it. Yet in general we all think modern medicine and modern surgery are pretty good things. But if some wacko who can't think reasonably about what co-redemptrix might mean wants to promote Mary to Divine status, then we should throw out the decision and usage of the united Church since middle of the fifth century. Are there no Protestant teachings perversions of which have led to Spiritual disaster?
OR, try it again: The Church is a hospital for sinners, not a society of the elect. The disease is so virulent and so pandemic that even he hospital staff are infected, and one way or another they will show symptoms of illness. Sometimes a particular manifestation of the illness will crop up with the same symptoms in a number of different people.
On-lookers say, "I don't want to go to THAT hospital. Every one there is SICK!" It's like the problem with assessing hospitals on the basis of how many people die there. When I was a Chaplain at MGH, we had cases which other hospital s couldn't figure out sent to us, and our geniuses could only figure out some of them, so we had a lot of people die. Our high rate of death was precisely BECAUSE we were a good hospital, almost a hospital of last resort.
So the novel perturbations of sound doctrine and the bouts of Mariolatry out there on the fringes are, to me, as much an indication of the validity of the doctrines and of the RC church in general as anything else.
If we never leave the house, we won't get in car wrecks. WE won't get anywhere either. If we don't enter into Marian devotion, we won't risk Mariolatry. We'll miss a lot too.
So likewise with at least some doctrines. WE don't prove them from Scripture, but once we assume them, we find we can make sense (as we see it anyway) of Scripture, our lives, our relationship with God, and so forth. That's kind of a global observation which MIGHT advance some understanding about why, when somebody says,"You can't prove such and such from Scripture," we don't get all upset and start scurrying off after proof-texts. So when we read Kecharitomene we don't say,"Ah HAH! See there?" Rather we say,"And HOW!" (Always provided that where I say "we" I mean "moiself".)
As to works and merit and grace and all the rest of it: It just occurred to me that we've been dealing with this question since St. Paul. For about a quarter of that time, some Protestants have commandeered the conversation and set the terms of discourse. And the Calflicks, with wonted stubbornness, have lifted the hems of our skirts and said that we weren't going to play in THAT mud, not like THAT!
SO maybe we need to back off and reconsider the conversation a bit.
And my contribution is something like this. Today Owing to Amtrak being, well, like Amtrak often is, I am going to drive my wife and daughter 300 miles into Maryland to my in-laws, and turn around and come back. (The funeral arrangements have not yet been made.)I am going to work hard. I do not think I would get to be with the wife and kid and the in-laws, or to see beautiful Maryland on this lovely day if I did not work hard in this way.
But I don't think I'm responsible of my family or the scenery, and I categorically refuse to take responsibility for Maryland. Family, sights, the rest ... all gifts. Even the desire to spend time with them and the willingness to suffer all the ill-effects of sitting down for however many gazillion miles ... all gifts. I pity the father who does not want to do such things and I consider myself lucky, indeed 'gifted', even to want, much less to be able, to do them.
EVERY good gift comes from God, every single one, including the enjoyment, the desire, the use, the embrace, and the gratitude. It's all gift, all of it. Or, perhaps better, it's all giving like a dance where a jewel is handed from dancer to dancer.
Now within that over-arching structure of "grace upon grace" there are some graces which operate, so to speak, through my will. Our Lady said, "Fiat," and what happened in response was not caused or earned by her saying so, and in any event her saying so was yet another sign and operation of the grace with which she so wonderfully endowed. I grumble, "Well, if the train is 5 hours late, I can drive you." But the joy and happiness, the deepening of family ties is entirely out of proportion to my consent, and even my consent was given with my sleep-ridden pre-coffee mind and will and I wouldn't dream of taking credit.
The preceding mess is what I being to the table of the merit and grace conversation. Because I am comfortable with paradox, I like to say that even the merit is a grace.