A large majority of the country’s more than 7,500 coronavirus patients are Shincheonji members in Daegu, a city in the southeast, or people who had come into contact with them. An additional cluster of cases has emerged in Cheongdo, a county near Daegu that is Mr. Lee’s birthplace and a regular pilgrimage destination for his followers.

The church has protested what it called “scapegoating” by South Koreans eager to discredit what had been the fastest-growing religious sect in the country, as other big churches worry about declining membership.

“The entire society has gone berserk against our church since the virus outbreak,” said Lee Young-Soo, 54, a Shincheonji member whose sister, a fellow church member, died after having fallen from her seventh-floor apartment in the southern city of Ulsan last month. Ms. Lee said her sister had confided that her husband’s long-running abuse over her church had intensified after the virus outbreak.

Another Shincheonji member who church officials said had suffered spousal abuse, a 42-year-old mother of two, died after having fallen from her 11th floor apartment on Monday night. The police are investigating both cases.

“The society is so wrong, and I am so saddened,” Ms. Lee said.

Still, the church is inextricably linked to the spread of the affliction in South Korea, one of the largest outbreaks outside China.