How we cite our quotes: (Day.Story.Page)
Quote #4
If we were to spend our money on our own pleasures, the friar would no longer be able to idle away his time in the cloisters; if we were to go pursuing the ladies, the friars would be put out of business; if we failed to practise patience and forgive all wrongs, the friar would no longer have the effrontery to call upon us in our own homes and corrupt our families. (III.7.244, Emilia's tale of Tedaldo degli Elisei)
Tedaldo voices the most common criticisms against the clergy: they're money-grubbing, lazy womanizers who benefit from the Christian philosophy of forgiveness when they've taken advantage of their parishioners' wives. They encourage tithing and sexual restraint so they can have the money and the women. Tedaldo, of course, is using this argument to discredit advice given against him by a friar to his beloved—so you should take it with a grain of salt.
Quote #5
This Friar Cipolla was a little man, with red hair and a merry face, and he was the most sociable fellow in the world. He was quite illiterate, but he was such a lively and excellent speaker, that anyone hearing him for the first time would have concluded, not only that he was some great master of rhetoric, but that he was Cicero in person or perhaps Quintilian. (VI.10.470, Dioneo's story of Friar Cipolla and the Angel's Feather)
Friar Cipolla (or "Brother Onion") is the forerunner of Chaucer's Friar, a pleasant fellow who knows how to work religion to his best advantage. Both fellows are good schmoozers, have magnetic personalities, and the gift of gab. But the fraudulent behavior of the friar is one of many reasons that Boccaccio and his fictional crew love to hate the clergy and how they play on the superstitions of their parishioners.
Quote #6
[...] the day before yesterday, when I went to the pardoning at Fiesole, I came across a hermitess, who as God is my witness [...] is the most saintly woman you ever met, and when she saw how terrified I was of the werewolf, she taught me a fine and godly prayer, telling me that she had tried it many a time before becoming a recluse, and it had always worked for her. (VII.1.488-489, Emilia's tale of Gianni Lotteringhi and the Werewolf)
As you might have guessed, there's no werewolf and no prayer to exorcise one from your property. What we have here is a clever wife exploiting religious superstition to cover the tracks of a lover who appears at an awkward moment. The fact that Tessa's trick works on her husband speaks volumes about Boccaccio's take on blind faith and superstition, especially among the lower classes.