“Some of you have been saying you want to live in biblical times,” Mr. Cahn said, pacing behind a lectern. Then he spread his hands wide. “Well, you are.”

Sitting at the end of a sleepy drive an hour from Manhattan, Beth Israel may look like any common suburban church. But the center has a highly unusual draw. Every weekend, some 1,000 congregants gather for the idiosyncratic teachings of the church’s celebrity pastor, an entrepreneurial doomsday prophet who claims that President Trump’s rise to power was foretold in the Bible. ...