Michael Horton:

What would things look like if Satan really took control of a city? Over a half century ago, Presbyterian minister Donald Grey Barnhouse offered his own scenario in his weekly sermon that was also broadcast nationwide on CBS radio. Barnhouse speculated that if Satan took over Philadelphia, all of the bars would be closed, pornography banished, and pristine streets would be filled with tidy pedestrians who smiled at each other. There would be no swearing. The children would say, “Yes, sir” and “No, ma’am,” and the churches would be full every Sunday…where Christ is not preached.

— Christless Christianity, p. 15. (You can read the first chapter online for free.)