Fallen into heresy?
That is a false accusation.
The earthly incarnation of the 'second person' of the Trinity can quite easily enough (nowadays, anyway) be understood to not be divided as for the two natures. Not divided from time He was conceived within Mary, anyway. Prior to that time of conception -- you tell me -- did He have a 'human' nature? If so, then HOW?
I said nothing that is opposed to the concept of the 'two natures' being in inseparable unity. Along lines of the type of accusation you just made, I said only that Mary was not herself the (capital S) Source of Christ's divinity, with it rationally following that the Source of Christ's own divinity is from nowhere else other than His real & actual Father.
I did not term the situation as Mary being restricted to being "mother of [only] the human nature of Christ", yet you put that within quotation marks as if I did. Don't be putting words in my mouth that I did not say...
I did however single her out as being the 'source' so to speak, of Jesus' human, physical nature. That is not the same as dividing the two natures in the womb ---where those two natures became as one inseparable (as far as I know).
It appears to me that you keep side-stepping how referring to Mary as say; mother of the Incarnate Christ, stops short of the necessary backpedaling one must engage in order to limit perceptions of the motherhood of Mary (in regards to her son, Jesus) be not only to the second person of the Trinity ~alone~ (not Mother of God the Father and The Holy Spirit too), but also only to the earthly incarnation of that same "second person" of the Trinity.
That can be so without there being anything like an automatic dissolving of the the two (fully human, and fully divine) natures.
I have demonstrated nothing of the sort just now, or even much previously, although there is a trap of sorts inherent with speaking of this issue.
People often are not careful and precise enough with their chosen wordings when they attempt to express from just where the two different 'natures' Christ is otherwise said to possess as His one entire indivisible nature and being come from. I suppose one could backtrack the human nature to having come from God too, through the human being known to us as the first 'man', Adam --in the first place-- BUT I JUST COVERED THAT ASPECT also.
So; for what you have just accused me of;
I've said nothing of the sort. Not even close. I've taken pains to avoid doing so.
You falsely accuse me amid continuance of yourself engaging in ranting and raving railing.
Something of that (cough-cough) nature has occurred ancillary to discussions of this type since Nestorius's position and argument was framed and decided upon prior to himself even arriving at the Council of Ephesus (431 AD), and a century prior to that in regards to the violence, the persecution even unto death of those who tended towards agreement with bishop Arius ---committed by supporters of bishop Alexander (of Alexandria) and the then deacon Athanasius just prior to when the Council of Nicea officially commenced.
Embedded in your multi-paragraph rant, are a couple of questions, which I will answer:
Mary, being a creature, is not the source or origin of the divinity of the Second Person of the Trinity.
The eternally-existing Second Person of the Trinity did not, from eternity, have a human nature. He began to have a human nature when he took flesh, and this occurred at the moment Mary conceived him in her womb.
Because Mary is the mother of Jesus Christ, who is God, it is accurate and appropriate to refer to her as the Mother of God.
I'll have a couple of pointy rocks,three flat ones and a packet of gravel.
Would be a lot less grief if we simply reffered to Mary as the Word does.
Hebrews 13:9 Be not carried about with divers and strange doctrines. For it is a good thing that the heart be established with grace; not with meats, which have not profited them that have been occupied therein.