CathInfo.com

I used to use this argument too, but there are some theologians who hold BOD to not be de fide but a lesser theological note. Even those theologians who do hold BOD to be of a lesser qualification still consider it’s denial to be a mortal sin. So, all of those people who deny BOD are, at the very least, guilty of mortal sin as there are no theologians, post Trent, who support their position.

Some may argue that theologians aren’t part of the teaching Church, but this can’t stand since some of them are bishops and even Doctors of the Church, as in the case of Saint Alphonsus, thus part of the Church teaching. Also, the theologians writing post Trent were approved by the Church and Her popes and none have been corrected, let alone censured, for teaching what Trent taught about BOD.

As well, there are lots of things in the Catechism that are not "de fide" but still mortal sins to deny!  The Church doesn't label each because HELL is HELL.

Do you know that going to purgatory means being saved eternally? That aspect has nothing to do with the OP.

Trent teaches: If any one denies, that, by the grace of Our Lord Jesus Christ, which is conferred in baptism, the guilt of original sin is remitted; or even asserts that the whole of that which has the true and proper nature of sin is not taken away; but says that it is only erased, or not imputed; let him be anathema. For, in those who are born again, there is nothing that God hates; because, there is no condemnation to those who are truly buried together with Christ by baptism into death; who walk not according to the flesh, but, putting off the old man, and putting on the new who is created according to God, are made innocent, immaculate, pure, guiltless, and beloved of God, heirs indeed of God, but joint heirs with Christ; in such a manner that absolutely nothing may delay them from entry into heaven

Trent teaches: But though He died for all, yet all do not receive the benefit of His death, but those only to whom the merit of His passion is communicated; because as truly as men would not be born unjust, if they were not born through propagation of the seed of Adam, since by that propagation they contract through him, when they are conceived, injustice as their own, so unless they were born again in Christ they would never be justified, since by that new birth through the merit of His passion the grace by which they become just is bestowed upon them.”

St. Alphonsus says: "Baptism of desire is perfect conversion to God by contrition or love of God above all things accompanied by an explicit or implicit desire for true baptism of water, the place of which it takes as to the remission of guilt, but not as to the impression of the [baptismal] character or as to the removal of all debt of punishment"

So these people St. Alphonsus is speaking of are not "born again" through BOD, according to Trent. There is "something" (debt of punishment) that delays them from entry into Heaven. But Trent teaches that unless you are "born again" you would "never be justified".

Trent teaches: If any one denies, that, by the grace of Our Lord Jesus Christ, which is conferred in baptism, the guilt of original sin is remitted; or even asserts that the whole of that which has the true and proper nature of sin is not taken away; but says that it is only erased, or not imputed; let him be anathema. For, in those who are born again, there is nothing that God hates; because, there is no condemnation to those who are truly buried together with Christ by baptism into death; who walk not according to the flesh, but, putting off the old man, and putting on the new who is created according to God, are made innocent, immaculate, pure, guiltless, and beloved of God, heirs indeed of God, but joint heirs with Christ; in such a manner that absolutely nothing may delay them from entry into heaven

Trent teaches: But though He died for all, yet all do not receive the benefit of His death, but those only to whom the merit of His passion is communicated; because as truly as men would not be born unjust, if they were not born through propagation of the seed of Adam, since by that propagation they contract through him, when they are conceived, injustice as their own, so unless they were born again in Christ they would never be justified, since by that new birth through the merit of His passion the grace by which they become just is bestowed upon them.”

St. Alphonsus says: "Baptism of desire is perfect conversion to God by contrition or love of God above all things accompanied by an explicit or implicit desire for true baptism of water, the place of which it takes as to the remission of guilt, but not as to the impression of the [baptismal] character or as to the removal of all debt of punishment"

So these people St. Alphonsus is speaking of are not "born again" through BOD, according to Trent. There is "something" (debt of punishment) that delays them from entry into Heaven. But Trent teaches that unless you are "born again" you would "never be justified".

Born again, means sanctifyig grace. I am taking about "de fide", not aspects of the teaching.