DAEGU, South Korea—To enter the nine-story Shincheonji Church of Jesus building Feb. 16, the 61-year-old woman needed to press her finger into a digital scanner.

She was nursing a sore throat and a fever, local health officials report, and any doctor would have advised her to stay home—especially as the new coronavirus lurked in South Korea. But skipping Sunday service wasn’t an option: Church leaders take attendance by checking a follower’s Shincheonji-issued photo ID, said current and former church members.

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