Good post!
Except that it doesn't apply to you. He's talking about (or appears to be talking about) a requirement for actual conversion to Catholicism. I say "appears to be" because the tendency of BoDers is to pay lip service and then two sentences later contradict the whole thing. So that remains to be seen.
Bp. George Hay (1729-1811):
“Q. What opinion, then, may be formed of the salvation of any one, in particular, who is out of the true Church of Christ, and lives in a false religion?
A. In answer to this, I may ask another question: What opinion would you form of the salvation of one who is living in the open state of mortal sin, such as adultery, robbery, impurity, or the like? No one could presume to say that that man will certainly be lost; but every one may say that, if he die in that state, without repentance, he cannot be saved. If it be the will of God positively to save him, He will, before he die, give him the grace of sincere repentance; because God Almighty expressly requires from sinners a sincere repentance as a condition without which they cannot be saved: ‘Except ye repent,’ says He, ‘ye shall all likewise perish,’ Luke, xiii. 3. The same is to be said of a person who is out of the true Church, and lives in a false religion. If he die in that state he cannot be saved; and if it be the will of God actually to save him, He will undoubtedly bring him to the true faith, and make him a member of the Church of Christ before he leaves this world; and the reason is the same as in the other case. God, as we have seen above, requires all men to be united to the Church by true faith as a condition of salvation, and therefore daily ‘adds to the Church such as shall be saved,’ Acts, ii. 47. Now, though a man be ever so great an adversary to the Church of Christ at present, or ever so great a sinner though a member of the Church, yet, as no man can know what God may be pleased to do for either before he die, so no man can pronounce and say that either the one or the other will be lost; for, if God please, He may give the light of true faith to the one, and the grace of true repentance to the other, even at their last moments, and save them…
Q. But, in the case proposed, if a person, in his last moments, shall receive the light of faith from God, and embrace it with all his heart, would this suffice to make him a member of the true Church in the sight of God?
A. Most undoubtedly; the case is the same in this as in that of baptism. Though Jesus Christ expressly says, ‘Except a man be born again of water and the Holy Spirit, he cannot enter into the kingdom of God,’ John, iii. 5, which establishes the absolute necessity of baptism for salvation; yet, suppose a heathen should be instructed in the faith of Christ, and embrace it with all his heart, but die suddenly without baptism, or be taken away by infidel friends, or put in absolute impossibility of receiving baptism, and die in the above dispositions with sincere repentance and a desire of baptism, this person will undoubtedly receive all the fruits of baptism from God, and therefore is said to be baptized in desire. In like manner, suppose a person brought up in a false religion embraces with all his heart the light of the true faith, which God gives him in his last moments, as it is absolutely impossible for him in that state to join the external communion of the Church in the eyes of men, yet he certainly will be considered united to her in the sight of God, by means of the true faith which he embraces, and his desire of being united to the Church, were it in his power.”
As has been stated many times, what the bare minimum that must be believed in order to have supernatural faith is disputed:
“Whether the knowledge of the Divine Trinity and of the Incarnation is indispensably necessary (necessitate medii) is a matter of dispute among theologians.”
The Casuist: A Collection of Cases in Moral and Pastoral Theology (Nihil Obstat and Imprimatur, 1906).
What we do know however is that those who are in invincible ignorance of the Catholic Church, who receive supernatural faith and charity before their death are united to the Catholic Church in God’s eyes (the post on membership in the Church explains this in more detail).
“If I were asked to be more definite, and to point out those who are in good faith, and in a state of invincible ignorance, whether they are numerous, whether such and such persons, who, as far as their friends could see, died in a belief different from the Catholic Church, are lost, I would say, as every well-instructed Catholic must say, I know nothing about the fate of individuals. It is God alone who sees the secret of hearts. No one can tell what passes, at the last moment, between the soul and God...It is certain that judgment belongs to God alone; and that we dare not say, of any one, though his whole life may have been polluted with sin, that he is lost for all eternity. ‘Who art thou that judgest another man's servant? to his own master he standeth or falleth; and he shall stand: for God is able to make him stand’ (Rom. xiv. 4).”
Catholic Christianity and Modern Unbelief (Imprimatur, 1884).
For a more in-depth comparison regarding ecclesiology:
http://www.traditionalmass.org/images/articles/ecclesiology.pdf