uncle mikey believes that the tune is closer to traditional melodies of eastern India, not western, so although Sundar's story is a great inspiration, he thinks that the song was written instead by the Garo (the tune is almost a combination of Kumbaya and The Ballad of the Green Berets if you think about it; in a broad context, the lyrics too for that matter). As for the conclusion of the Garo story, the community of head-hunters was so amazed at the awesome power of an ancient faith from a far off land that could support the supernatural strength and sacrifice shown by the Christian family while they were martyred that the entire tribe thereafter converted to The Way. Here are the lyrics: I have decided to follow Jesus, Tho' none go with me, still I will follow, The world behind me, the cross before me, No turning back, no turning back.
