Massachusetts-based MassResistance has published a nearly 600-page book warning America about the dangers of gay sex to society.

In The Health Hazards of Homosexuality: What the Medical and Psychological Research Reveals, the vehemently anti-LGBT group's leader Brian Camenker encourages American society “to take a step back, understand what the normalization of homosexuality has brought in its wake, and reconsider the course we're on.”

In 2015, Camenker declared “war” on the LGBT rights movement, saying that God has a “very brutal” set of rules “for people who want to tear down society, who want to push immorality, who want to tear down the moral structures of society.” They “must be destroyed,” he said.

In the book's introduction, the group asserts that gay sex is hurting society.

“The American public is not being told how dangerous homosexuality is to the physical and mental health of its practitioners, as well as to our larger society. Rather, homosexuality is now generally presented as normal, respectable sexual expression which can be engaged in safely.”

“In fact, this normalization of sodomy and other dangerous practices requires our society to engage in mental gymnastics which severely distort our social, commercial, and legal interactions. Approval of homosexuality is a capitulation to irrationality which profoundly affects our society,” the book's introduction reads.

According to Right Wing Watch, the group was selling its book earlier this month at Values Voter Summit, the gathering of social conservatives attended by President Donald Trump.

(Related: At Values Voter Summit, Trump praises DOJ guidance on “religious freedom.”)

Camenker makes it clear that he wants people to use the book as a political weapon to deny LGBT rights. “Demands for 'gay rights' or 'LGBT rights' or 'gay marriage' should be answered … by noting the unnatural, unhealthy and repugnant character of GLB sexual practices and associated public behaviors,” he wrote.

According to Right Wing Watch, the book asserts that “homosexuality is really about sodomy,” “homosexuality is a mental health disorder,” and “transgenderism is a mental disorder.”

“The book devotes hundreds of pages to sexuality, sex practices and sexually transmitted diseases, with about 100 pages of footnotes meant to lend an air of scientific authority,” Right Wing Watch's Peter Montgomery wrote.