In countless trips through the African bush, Missionaries Doug and Evelyn Knapp have, between them, survived hepatitis, malaria, typhoid fever, other tropical maladies and even an encounter with spear-wielding assailants. Their trials have not been in vain. In the past decade, a revival led by the Knapps in Tanzania has resulted in the baptism of 40,212 converts, 14,409 of them in the past year.
The energetic Knapps, agriculturalists sponsored by the Southern Baptist Convention, are among the record total of 39,309 U.S. and Canadian Protestants engaged in overseas mission careers. Adding "short-term" workers, who usually put in stints of less than...