Granted, some big-time evangelists who founded superchurches have been caught up in scandals and defrocked by the press as crass profiteers.

Notable real-world exceptions have been the Reverends Billy Graham and William Schuller, but that’s going back a couple of generations. Those preachers ministered mainly to The Greatest Generation at a time when national surveys estimated 90 percent of Americans identified themselves as Christians. These days, that survey number has dropped to around 60 percent.

Those two respected leaders have passed on, and their sons are carrying their organizations forward. Their ministries have not so far been beset by scandals, but the main plotline of The Righteous Gemstones has the widowed Dr. Eli Gemstone (John Goodman) grooming his two sons to take over his worldwide evangelist movement – including a grand strategy to co-opt small-town congregations the way big corporations buy out their fledgling competitors.

A major subplot in the series has Dr. Gemstone flashing back to fond memories of the co-ministry he conducted with his wife Aimee-Leigh Gemstone. Real-world models for the couple might have been Jim Bakker and his wife Tammy Faye Bakker (Messner). Jim was eventually sent to prison on convictions of fraud and conspiracy. (As of this writing, actress Jessica Chastain has just won the SAG Award for her leading role in The Eyes of Tammy Faye, which I haven’t yet seen but from press clippings seems laudatory overall.)

HBO may be trying to recapture the dysfunctional-family intrigues of its highly successful series Succession, which was about schemes and betrayals centering on a patriarch whose business empire resembles Rupert Murdoch’s. But while that clever family is as sophisticated as they are phony, the Gemstones come across as unscrupulous hicks who got rich leveraging the herd-like mentality and the tax-free status of megachurches.