Explanation.

The Bible is a book of laws that everyone should follow by default. (Even without the book, it's clear what you can and cannot do.)
Those who follow it are fools, because smart people know everything without it. And those who react too strongly to these people and to religion in general are also fools, because it's just a relic of the past that was meant to help control and manage people. It's true that it still works today, but it seems that some people just need an incentive not to sin.