Let me change the verse reference:
Now after this verse you could have said, just as you said before, But what I am saying, is how does it show the (in this case) the Son of Man and God are two different entities? It does it by saying that they are visible. Problem: God is Spirit and therefore is not visible. So in order to make the connection that it proves two entities, one must also accept that one can visibily see God. Unless one can visibly see God, one cannot use this verse to prove two entities because it is on the basis of a visual clue that one makes the observation.
So also, in the passage we are discussing,"No one has ever seen God, but God the One and Only, who is at the Father's side, has made him known." (John 1:18), to say that this proves two entities, requires that we see a distinction between the Father and God. How is this achieved if not by saying that because he is literally at the side of the Father he cannot also be the Father. Whereas if this is understood metaphorically, we could still have a distinction of persons without having to have a distinction of beings?
Not neccessary. Just because the verse mentions side by side it does not mean that it has to be visible as this is information and in your view by God Himself. Being told about something true does not require neccessary vision of that thing. A bling man can be side by side with a seeing one and although he does not see this does not mean that he can not diffrentiate between the two. So what I am saying is that confirmation of vision is not neccessary in and of itself to prove difference in entities.
Remember that one of the things that Jesus said after his resurrection (according to the bible) was that he said to his desciples: Handle me and see for a spirit hath no flesh and bones. Now according to the bible understanding, resurrection is only in the spirit form. So do we understand by this that since they were able to see him and even touch him and give him to eat that he was not resurrected? Or this was metaphoric?
So all the talk about spiritual form and literal and metaphorical is vast in the bible and affirming one meaning of one verse means denying another verse with the same meaning. Of course if you look for consistencies. The other way is to subject every meaning to the doctrinal belief one follows. In this case although there will be no apparent contradiction, the danger of such is that whoever does not agree with you can prove exactly the same and even using the same verses. So I guess it comes back at your beliefs again.