It appears after some research that we are not obligated to believe that the canonizations of saints are infallible.
I do believe it, but we are not obligated to.
Some people say, and CM appears to be one of them, that Popes are only infallible when teaching on matters of faith and morals from the Magisterium and that canonizations do not fall into that heading. Since revelation was completed at the time of the Apostles, and the apostles leave no clues about the canonization of saints, that leads us to the conclusion that Popes can err in canonizing saints.
Where does it say that the Pope is infallible in the Apostolic revelation, though? "You are Peter, and upon this rock I shall build my Church." Fair enough. How about the fact that the apostles infallibly recognized EACH OTHER as apostles, and therefore, as saints? Would not this suggest that a Pope and Successor of St. Peter infallibly recognizes saints as saints?
Okay, it's not a dogma yet. But I think there might be proof in apostolic revelation that the Pope is infallible when canonizing saints. I believe this will be revealed one day.
Certainly God allows the devil to perpetrate fraudulent 'miracles', and if these are investigated they are certainly easily discovered as being so. I would not doubt that the devil uses such 'miracles' for the purpose of leading souls astray.
We are skeptical about miracles and stigmata because our time is so full of hoaxes, as Christ predicted it would be. But someone like St. Francis didn't just bear stigmata, he went out and risked his life to convert Muslims, he did all kinds of great works. The modern Catholic is besieged with false prophecy and false miracles but don't let that make you think that the miracles of the canonized saints are just debased pieces of cheap theater like most of the "miracles" of our own time.
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But you are right that the saints can err. I'm surprised no one has mentioned it yet, but St. Thomas was skeptical about the Immaculate Conception, as were St. Bonaventure and St. Bernard. They were wrong, but forgivably so, because the Immaculate Conception was not yet a dogma.
And guess what? It was never a dogma that all the unbaptized go to hell, despite how you try to make it sound. Some people felt they did; others kept their own counsel and left it to God to judge.
After several more centuries, it is now dogma that the unbaptized may -- MAY -- indeed be saved. You know the arguments, so I will spare you the Catechism of your proposed anti-Pope from 1917 and our side's interpretation of the Council of Trent.