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[QUOTE 3344503, member: 45"]It's the tune from an old hymn. Which may mean that it originated from a secular tune yonks ago. Can't pinpoint the hymn though.[/QUOTE]
I think this is right. It sounds too much like a US revivalist hymn for it too be a coincidence, and the use of Christian material is (tiresomely) common among anti-religionists wanting to make a point. I suspect it's in Moody and Sankey, but I don't have a copy.
The third line is the same as the third line of 'Infant Holy', which is Czech, but it's a simple sequence, so that's probably coincidence.