I will quote the Baltimore Catechism since it is more well-known. My apologies for the considerable length of the quote; the Catechism was quite thorough in this question.
Well, to be fair, you’re not quoting the Catechism here. You’re quoting from “An Explanation of the Baltimore Catechism”, by Rev Thomas L Kinkead. So, the teaching of the Church in this case is simply “Q. are all bound to belong to the Church? A. All are bound to belong to the Church, and he who knows the Church to be the true Church and remains out of it, cannot be saved.” The rest – that is, what you’ve quoted here – is simply Kinkead’s commentary on that question.
In any case, even Kinkead’s commentary, he’s talking about
mortal sin, which, of course, is defined in terms of grave matter, full knowledge, and deliberate consent. One would have to be able to demonstrate that a Christian has ‘full knowledge’ of a grave sin, and commits that grave sin with deliberate consent, in order to conclude ‘mortal sin.’ That’s problematic, it seems, if the person demonstrably does not have the fullness of the truth.
Kinkead is correct, of course, that one who dies in mortal sin is condemned. So, he’s speaking from the mind of the Church when he writes, “if, then, we found a Protestant who never committed a mortal sin after Baptism, and who never had the slightest doubt about the truth of his religion, that person would be saved.” (After all, we can produce doctrinal statements of the Church that assert precisely this notion.) However, he then gives his personal opinion: “I am giving you an example, however, that is rarely found.” (This, by contrast, is never found in magisterial documents. It’s his own opinion.)
So, if you want to base your opinions on the teaching of the Church, you’ll still have to produce them; you haven’t done so, yet. On the other hand, if you want to base them off the opinions of a single priest (regardless how erudite he might have been), then that’s your business…
