Protestants generally believe that faith in Jesus as Savior is sufficient to obtain eternal salvation. The Catholic view, as usual, is complicated.
A baptized confirmed Catholic, who practices the faith, believes what the Church teaches, and goes to Mass regularly might still not obtain salvation. Baptism brings us into the state of grace, but we can still lose that state by committing an actual mortal sin. Everyone who dies unrepentant from actual mortal sin goes to Hell.
A Catholic can return to a state of grace after actual mortal sin by perfect contrition (sorrow for sin out of love for God and neighbor) and Confession, or by imperfect contrition and Confession. If Confession is not available, then perfect contrition alone suffices (with the desire, at least implicitly, for Confession if it should become available).
But how many Catholics go to Confession regularly? Very few. I see many people at Mass every week, and there are multiple times to go to Mass each weekend. Confessions are held only on Saturdays in most parishes, and very few people show up.
How many Catholic souls are lost to Hell because Catholics do not generally go to Confession at all?
Just because you are Catholic, it doesn’t mean you are saved. You have to cooperate with the grace of God to remain in a state of grace, to die in that state, and also hopefully to avoid a long stay in Purgatory.
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