This is great. My contention is that there are boodles of blues, R&B, and other songs based on specific spirituals that remained obscure enough that the relationship was not immediately o-bivious.
It is funny because we are doing these in church, and I add new verses all the time, and so I am no more a purist that Sam Cooke. But (I hope) I am also no more of a "folk sinner" than he, and others who have taken these great items and put them to work, to give them new life relevant to today.
Will you check the tune once it's posted and see if it's the same, albeit bloozed-up in interpretation?