Grace doesn’t only flow through the sacraments, not even according to CC teaching (someone correct me if I’m wrong). Many protestant denominations/individuals believe in “enabling” grace. This is a grace that enables an individual to choose God, it enables faith… sometimes this grace is held up vs. irresistible grace that basically forces faith.
You are correct that this is a view of some Protestants, most notoriously Presbyterians. Specifically this is the “reformed view.” I have no idea why it is called that since they claim it was also the view of the apostles. They claim the following principles:
T. Total depravity of man. This means that man’s depravity is so complete he is incapable of seeking God on his own
U. Unconditional election. This means God chose in advance those he would save and damned the rest before they were even born.
L. Limited atonement. It stands to reason (internally) that Jesus would then only die for those he intended to save
I. Irresistible grace. God is omnipotent and draws only the elect with his irresistible power. The rest may receive resistible invitations to grace but have no power from God to respond positively.
P. Perseverance of the saints. God is omnipotent and he does not quit on his elect. Whatever the temptation or season of backsliding He will ultimately prevail on their souls to endure in faith to their final glorification in the resurrection.
People who hold this view devoutly tend to see it in every chapter of the Bible but a central reference is Romans 8:28-39.
Frequently this doctrine gets simplified to OSAS but it bothers me because there is a serious pandemic of false doctrine with a lot of adherents and supported by a lot of bible twisting. That includes those who hold to OSAS but don’t actually know the reformed view. For example, Jesus tells Nicodemas, “if the son of man be lifted up, I will draw all men to myself.” The Tulip people than object that all didn’t mean all–just all the elect. The hermeneutical gymnastics wax complex and absurd.
My own view is that God saves everyone he can without violating the agency he gave us. If He could make us love Him, it would’nt be love but an abomination. So He woos us like a man with a maid and how we respond is up to us, for better or worse–like a man with a maid. I think my view is like the catholic view but I am open to correction here. To the extent we may depraved God still helps everyone have enough grace that they could choose to turn to Him. Nobody who is willing to enter by the narrow gate and walk the difficult path that lads to life is turned away and Jesus is the lamb of God who died for the sins of the world.