A modern Saint Francis, Sundar Singh (1889-1929) left the wealth of his home at sixteen to live as a sadhu, or wandering holy man. His beggar-like existence, his intense devotion, his mystical encounters with Jesus, and his simple yet profound parables became the stuff of legends. No one who met him - including the thousands who flocked to hear him during his visits to Europe, the Far East, and the United States - remained unaffected.

Known in his lifetime as India's most famous convert to Christianity, Sundar Singh would not approve of that characterization. He loved Jesus...