Then there's the Ranter belief that the light of Christ within every person was so important that true believers could never sin, and if they committed theft, adultery etc. it was actually perfectly all right with God—from a modern perspective this one seems like kind of a recognition of the fact that contemporary definitions of 'sin' often had little to do with actual wrong, but also kind of obviously full of terrible implications.

Wow. Yes, now that you say it, I think I've heard of that one before. Obviously full of terrible implications, yes! But at the same time, one wishes those Puritans would relax a bit when it comes to some 'sins'...