Animal rights activists often conjure up extreme stunts, such as profane billboards, public nudity and even acts of domestic terrorism, to get media attention and promote a vegan agenda.

Now activists are focusing on an unlikely place — your local church — to create confusion about the morality of eating meat and modern animal agricultural practices. Even in rural Iowa, farmers say they’ve been shocked to see “Meatless Monday” promotions and messages attacking livestock farming in their local church bulletins and Bible study guides.

A newly released book, titled “What Would Jesus Really Eat?”, aims to help livestock farmers, and all meat...