You're very quick to stamp heresy on what you disagree with.
I'm calling heresy what is heresy. Aphthartodocetism was a 6th century heretical position proposed and taught by Julian of Halicarnassus which taught that Christ, before the resurrection, did not have a corruptible body but always had an incorruptible one. The term "Aphthartodocetism" comes from two words, aphthartos meaning "incorruptible", literally "unable to decay" and dokeo meaning "to seem"; an earlier heresy Docetism had taught that Christ only "seemed" or "appeared" to be human but was in fact an entirely divine being, a kind of divine hologram or phantasm who had no real body at all (this is the heresy which St. John is combating in his epistles, these are the ones he calls "antichrists" who deny that Jesus came in the flesh). Thus the Aphtartodocetae taught that Jesus only "seemed" to have a body that could suffer, it only seemed mortal, but was in fact an entirely immortal and incorruptible body that could not suffer and it was only by a specific extraordinary occasion that He was able to be crucified and die.
I'm not calling this heresy because it simply disagrees with what I personally believe; I'm calling this heresy because it's heresy and has been a recognized heresy for nearly 1500 years.
I also charged your statement about God turning away from Christ and the Spirit departing Christ heretical, because it fundamentally undermines and goes against the fundamental teachings of the Trinity in which is confessed that Jesus, as the only-begotten Son of God the Father is homoousios--of one being/nature/substance/essence--with the Father. The Father, Son, and Holy Spirit are united in their one indivisible and inseparable Divine Essence. The Spirit can't depart Christ because the Spirit and Christ are united together in the unity of their Being with the Father--one God. The Son was never without the Father or the Spirit. By saying that the Father turned away from Christ, or that the Spirit departed from Christ is to say that there existed a division, a severing, of the unity of God's own Essence. And that's a major problem. It is a major Triadological error to say that the Father ceased to be united to the Son; the Father did not turn away from the Son, that isn't why He cries "Eli Eli, lama sabacthani!"--for one Christ is quoting Psalm 22, and for another we merely need to recognize that Christ, being both God and man was able to feel, to suffer, and experience those things common to all men. Our Lord Jesus, though very God, one in being with the Father from all eternity, none-the-less was human (just like you and I) for this reason He could experience joy, sadness,
and even the dread of the cross.
So, yes, on these two accounts I stated that what you were promoting was heresy, because these are directly at odds with orthodox Christian teaching.
Most of what you say, I do not disagree with. However, God is our savior only through the perfect humanity of Jesus. Jesus died voluntarily, his mortality was his choice and was his mission, but not a foregone conclusion without the cross.
And that encompasses the entirety of the Incarnation, not just one brief moment. He was conceived a mortal human being, the same as you and I. The only difference between Him (as far as His humanity is concerned) and us is that He did not sin; but He was still subject to the stain of sin that exists among all of us--and indeed, the reality of it as it is present throughout all creation.
His redemption is for all creation, not just humanity since death, brought in by Adam, permeates all creation.
Bingo. Which is why saying that in order for Jesus to be mortal required that He be sinful is false, He was not sinful; and when he bore the weight of our sin on the cross it was not because He suddenly became a sinner on the cross, it is that the full weight of human sin fell upon Him and He, even in dying, crucified it and rendered it inert and inept and by His rising destroying the power of sin, death, and hell and granting to us salvation, eternal life, and resurrection.
Christ is risen from the dead,
Trampling down death by death,
And to those in the tombs,
Bestowing life.
-CryptoLutheran