Sorry for the vague question. I was watching a debate in youtube a few days ago and someone said something like this:
but since God is good he cannot create anything evil. In fact this was an argument made by [prophet's name], a Persian man who claimed to be a prophet and he said that Muhammed's message was corrupt for this very reason, but that he had been sent to correct it
The conversation then moved on to other topics but I was left wanting to know more
I've been trying to find out who this person was but I come out empty handed. I also tried to find the video in question but I've watched several similar debates and they are long so I have not found which one it was
Who was this Persian prophet?
So I've given this a couple of days to see if anybody else joins in before totally derailing the question. Are you absolutely certain that this story was set shortly after Muhammad's death? There were several schools of theodicy (the attempt to explain why a good God allows evil to exist) that developed in early Islam, but none were led by a single individual claiming to be a prophet.
It sounds a bit like the founding premise of the Bahai Faith and Babist movements in the 19th Century - in which a Persian religious reform movement split into to new religious orders with similar claims of a founding prophet continuing the line of prophecy from Muhammad. Neither would ever suggest that Muhammad's own message was corrupt though, so I don't know if that's what the video may have had in mind. I can elaborate, but I don't quite know what I should be elaborating on or even if I know what was being referred to in the first place.