How did the plague affect people's faith in Catholic church?

Answer 1

It caused lots of problems. For one thing, lots of priests were dying, so there became an urgency to ordain more priests, and many of these new priests were not well formed in the faith and did not turn out to be good priests.

Answer 2

Roman Catholic AnswerIn the book, Seven Lies About Catholic History, by Diane Moczar (link for the book is below), in Chapter 6, "A Church Corrupted to the Core" Ms. Moczar discusses "The Difficult Centuries Preceding the Reformation", which would be the 14th and 15th centuries. These two centuries were "liberally punctuated with disasters of all kinds", one of which, was the Black Death, the greatest pandemic know to history. Along with the Hundred Years' War, climate change, debilitating famines: all of which, together, produced social discord and a decline in morals. Also, the papacy was going through its own black period, including the Avignon papacy. These and other problems all weakened the Church and her authority, and along with several pre-reformation heresies mostly based on older heresies such as the Cathars, paterenes, and others. The other movement that affected people and their view of the Church was a new nationalism that had been unheard of before. We see how this played out in England with Henry the VIII, and Luther in Germany. In sum there were many factors that were profoundly disturbing in society and affected the Church and the people. The thing to keep in mind is that AT NO TIME did the common man in pew call for a 'protestant reformation', or to put it in Ms. Moczar's words:

This is the essential point: the Catholic religion of the masses was destroyed against their wishes. The Protestant Reformation was a revolution, and as another historian has remarked of revolutions, they are never really made by "the people". Certainly in England the changes brought by the religious revolution, far from being desired by the English people, were bitterly resented.