I think I could say black and you would automatically say white my friend. Go get some sleep and we can pick up tomorrow. Good night.
I do not accept just similarity of words used in personal sentences of various authors. This cannot be used as evidence, IMHO.
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I, personally, would be very interested in that council of Carthage and generally in era when arianism emerged. If such a verse was in the Bible in those times, they would certainly use it as one of main pillars in defense of Trinity.
On the other hand, if it is not clearly quoted (as clearly as other Bible verses) in those times, its a very serious evidence that it was not present in the Bible and that it was added later, probably because of this arian controversy.
So I would probably start here. I found some text of the council of Carthage online, but I am not sure if it is it. The verse was not quoted there.