A heretic is commonly defined as a person believing in or practicing religious heresy.

In religion, being a heretic is a major offense.
This is mainly during the early ages of the Catholic Rule in exploration Europe.

FEMA is the Federal Emergency Management Agency.

FEMA madde an incredible effort during the period of destruction after Hurricane Katrina ravaged the United States of America's east coast states.

The font size in the Bible is incredibly small and it is not common to see a person using reading glasses when reading the Bible.

Bo describes the glasses as "Ceremonial" which he uses as a targeted hyperbole. He refers on the overly valued moment the Mass indulges in when the time comes to read from the Bible in Mass.

The Book of Leviticus contains a great quantity of content that would be highly inappropriate to children.

In the Book of Leviticus there are:
Rules of sexual contracts and child sacrifice.
Rules of unlawful sex.
Rules of slavery.

Bo alludes to the rules of slavery in "when God, in verse 45, said that slaves are okay to buy".

The Book of Leviticus is rather infamous for its adult content and is highly innappropriate for children to read.

The Book of Leviticus:
Chapters 1-5 describe the various sacrifices from the sacrificers' point of view, although the priests are essential for handling the blood. Chapters 6-7 go over much the same ground, but from the point of view of the priest, who, as the one actually carrying out the sacrifice and dividing the "portions", needs to know how this is to be done. Sacrifices are to be divided between God, the priest, and the offerers, although in some cases the entire sacrifice is a single portion consigned to God - i.e., burnt to ashes.

With sacrifice and priesthood established, chapters 11-15 instruct the lay people on purity (or cleanliness). Eating certain animals produces uncleanliness, as does giving birth; certain skin diseases (but not all) are unclean, as are certain conditions affecting walls and clothing (mildew and similar conditions); and genital discharges, including female menses and male gonorrhea, are unclean. The reasoning behind the food rules are obscure; for the rest the guiding principle seems to be that all these conditions involve a loss of "life force", usually but not always blood.

Chapters 17-26 are the Holiness code. It begins with a prohibition on all slaughter of animals outside the Temple, even for food, and then prohibits a long list of sexual contacts and also child sacrifice. The "holiness" injunctions which give the code its name begin with the next section: penalties are imposed for the worship of Molech, consulting mediums and wizards, cursing one's parents and engaging in unlawful sex. Priests are instructed on mourning rituals and acceptable bodily defects. Blasphemy is to be punished with death, and rules for the eating of sacrifices are set out; the calendar is explained, and rules for sabbatical and Jubilee years set out; and rules are made for oil lamps and bread in the sanctuary; and rules are made for slavery. The code ends by telling the Israelites they must choose between the law and prosperity on the one hand, or, on the other, horrible punishments, the worst of which will be expulsion from the land.

Source:
https://en.wikipedia.org/wiki/Book_of_Leviticus

The sterotype:
All Catholics (or Christians) are all hyper-conservative, white, rich folk.

Bo also uses assonance in this with the use of "asses".

Bo insults the Mass, or the attendees of the Catholic Church on Sunday, on that they are all overweight.

Later on in the song, he goes on to mention "rich and white" so we can assume the Mass is also white and wealthy, as the stereotype follows.