I really like the story in John 1 and do not think it is of mixed pagan origin.
Jesus life is possibly the best story you could hope for, and it is pro interfaith. The complex 'logos' explanations and comparisons are a way of relating the story with pagans, but the expression 'In the beginning' is probably a 100% Jewish mystical usage. The beginning of Jesus ministry is considered a new creation, characterized by light coming into the world. The light, itself, judges darkness, as opposed to a human judge doing it. This really is an amazing interfaith paradigm. I don't know much about other religions, but I think from what I've seen this is pretty much a giant piece of tape connecting them all.
I sense there are many religions out there which can respect and benefit from this. This new creation of John 1 is created through Jesus, so he is the author and finisher of that creation in a sense -- though not the author of the word, nor of the creation in Genesis though he and 'his creation' is included as part of that creation. He is the light in John 1, which comes after the word. His followers consider themselves prizms of that light. Rather than being the word he is called 'the word made flesh'. Instead, the word dwells in us as the lampstand in a tabernacle. It is similar to the gnostic 'Divine spark' but not exactly. This word concept, while captured in Greek with 'Logos' actually is Jewish I suspect. Hark back to Genesis 1 where the creation was finished by seven spoken phrases. Despite the fact that we are all here, the end of our lives is included in the words spoken in Genesis and we are part of that 'Finished' creation from heaven's perspective. Similarly, Jesus is a new creation, part of the larger creation, of which christians are a part, a creation that is already finished though we humans do not yet perceive the end of it.
my grandfather john, a deepsea fisherman, quoted him verbatim when he was drunk and put the heeby jeebies in me; only when singing like a gaelic did l feel 'the light'.
the light and the word are definitely 2 concepts which all the religions have at their core; 'of which christians are a part' should have no place for this new inclusive 'story', since we all agree that all the extant religions seem to rub each other up the wrong way, particularly within the religions themselves.
this story cannot be sectarian.