SAINT-VALLIER, France — In Togo, the Rev. Rodolphe Folly used to conduct exuberant Sunday services for a hundred believers of all ages, who sang local gospel music and went up to him to offer what they had.

In this quiet town in Burgundy, he preaches to a more somber audience of about 40 gray-haired retirees in an unadorned 19th-century church that can accommodate up to 600 people.

“In my country, we applaud, we acclaim, we shout,” said Father Folly, a Roman Catholic priest who spoke in the living room of his modern, modest house. “Here, even when I ask people to shake hands, they say no.”

Father Folly, 45, has settled in this town of about 9,000 residents, assigned to replace an aging priest. He has brought his jovial smile and good heart to a place where religious practice is weak, as it is in many other areas of France. He is part of a battalion of priests who have come to France from abroad — from places like Benin, Burkina-Faso, Cameroon but also Vietnam and Poland — who now represent about 10 percent of France’s declining clerical ranks.