Paul Offit doesn’t mention Galton’s tongue-in-cheek experiment in “Bad Faith,” but he forcefully demonstrates that the children of people in faith-healing groups have higher mortality rates than those whose parents have their children vaccinated and seek medical help when they fall ill. Dr. Offit, a pediatrician at the University of Pennsylvania School of Medicine, is primarily concerned with the health of children who are the victims of their parents’ misplaced faith.

     Dr. Offit has no problem with religion: Indeed, he insists that it is also the hero of his tale of neglect and premature, unnecessary death. He knows his Scripture, his Jewish doctrine and his theology. Good faith is good, bad faith is bad. And, to his medical eyes, the bad faiths are those that either deny the existence of disease (Christian Scientists) or believe that when disease strikes it is a sign of sin or failing and therefore properly “cured” by prayer and repentance. His volume is a catalog of tragedies, some from his own practice, most from the public record, that need not have happened. For him, the old Puritan mantra of praising the Lord but keeping your powder dry is the sensible way.

     Most of Dr. Offit’s analysis is devoted to Christian sects, of which Christian Science is merely one. Thus the Faith Tabernacle Congregation in Philadelphia, the Faith Temple Church of Apostolic Faith in Milwaukee and other individual congregations, as well as larger groups such as Jehovah’s Witnesses and Seventh-Day Adventists, all receive Dr. Offit’s attention. The stories are depressing: children with diabetes who are required to abandon their insulin for prayer, children with bacterial meningitis prayed for but not sent to the hospital for antibiotics, hemophiliacs not receiving their blood transfusions, children exposed to lethal measles because they are unvaccinated. Sometimes the “therapy” is more aggressive: Terrance Cottrell Jr., an 8-year-old boy with autism, died of asphyxiation in August 2003 while being exorcised for his condition by the pastor of the Faith Temple Church.

     Although fundamentalist Protestant groups get the most attention, Dr. Offit does not confine himself to them. He recounts a horrifying story from 2009 of a 27-year-old mother of four, 11 weeks pregnant with a failing heart exacerbated by her pregnancy. Sister Margaret Mary McBride, director of the ethics board in a Roman Catholic hospital in Phoenix, allowed the woman to have her pregnancy terminated. To withhold consent would have been to orphan four living children, and the pregnancy would not have resulted in a live birth had the mother survived. For her decision, Sister McBride was excommunicated (though she was later reinstated), and the hospital chapel denied the right to celebrate Mass.

     On a lighter note, Dr. Offit doubts the reality of faith healing at Lourdes, but he accepts that pilgrims generally come away feeling better. The shrine is also good for the local economy in southwest France.

     Most medical evidence suggests that circumcision has positive benefits, both for the male and for his sexual partners. A Jewish ritual, metzitzah b’peh, dictates that the officiating rabbi suck the blood from the infant’s wound with his mouth. The procedure can and has spread syphilis and, more commonly, herpes to the infant. The ritual is practiced about 3,600 times each year in New York City. Because in this context it is a religious ritual, not a medical procedure, some Jewish doctors nevertheless defend it, despite its risks.

     Given this catalog of wastage, what is to be done? Dr. Offit has far too much respect for religious belief and practice to suggest, like some aggressive atheists, that the world would be better off without its religions. Freedom of religion is of fundamental importance to the fabric of American life. Consequently, he sees hope in the law. Parents should not be able legally to deny their children proper medical care. Much of the last part of “Bad Faith” is about this issue. Richard Nixon’s Watergate henchmen Bob Haldeman and John Ehrlichman (both Christian Scientists) managed to smuggle a religious-belief exemption into child-protection legislation in the 1970s, Dr. Offit recounts, and the consequences continue to surface. The pediatrician in Dr. Offit simply wants better legal protection for his patients.

     A second way forward is for individual changes of heart. The heroine of this powerful book is Rita Swan, a former Christian Scientist who watched her son sicken with a bacterial meningitis as she, her husband and fellow Christian Scientists prayed. She had already fallen afoul of her church for having an emergency gynecological operation, which saved her life, and when her son Matthew was at death’s door, she again broke ranks and took him, too late, to a hospital. Five years after Matthew’s death in 1977, she and her husband founded a child protection organization (Child Healthcare Is a Legal Duty) that has continued to work toward protecting children from religiously motivated medical neglect. Like many contentious issues, and any that involve the courts, this one is unlikely to disappear in the near future and certainly not before many more children will needlessly die.

     Mr. Bynum is the author, with Helen Bynum, of “Remarkable Plants That Shape Our World.”

Other notable reviews of Bad Faith:
The New York Times Review of Books
NBC News