Anyone who knows the Catholic religion to be the true religion and will not embrace it cannot enter into Heaven. If one not a Catholic doubts whether the church to which he belongs is the true Church, he must settle his doubt, seek the true Church, and enter it; for if he continues to live in doubt, he becomes like the one who knows the true Church and is deterred by worldly considerations from entering it.
In like manner one who, doubting, fears to examine the religion he professes lest he should discover its falsity and be convinced of the truth of the Catholic faith, cannot be saved.
Suppose, however, that there is a non-Catholic who firmly believes that the church to which he belongs is the true Church, and who has never–even in the past–had the slightest doubt of that fact–what will become of him?
If he was validly baptized and never commited a mortal sin, he will be saved; because, believing himself a member of the true Church, he was doing all he could to serve God according to his knowledge and the dictates of his conscience. But, if he ever committed a mortal sin, his salvation would be very much more difficult. A mortal sin once committed remains on the soul till it is forgiven. Now, how could his mortal sin be forgiven? Not in the Sacrament of Penance, for the Protestant does not go to confession…Does he know that without confession it requires an act of perfect contrition to blot out mortal sin, and can he easily make such an act? What we call contrition is often only imperfect contrition–that is, sorrow for our sins because we fear their punishment in Hell or dread the loss of Heaven. If a Catholic–with all the instruction he has received about how to make an act of perfect contrition and all the practice he has had in making such acts–might find it diffifult to make an act of perfect contrition after having committed a mortal sin, how much difficulty will not a Protestant have in making an act of perfect contrition, who does not know about this requirement and who has not been taught to make continued acts of perfect contrition all his life. It is to be feared either he would not know of this necessary means of regaining God’s friendship, or he would be unable to elicit the necessary act of perfect contrition, and thus the mortal sin would remain upion his soul and he would die an enemy of God.
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 relgion, that person would be saved; because being baptized, he is a member of the Church, and being free from mortal sin he is a friend of God and could not in justice be condemned to Hell. Such a person would attend Mass and receive the Sacraments if he knew the Catholic Church to be the only true Church…