Your reasoning is flawed. What possible reason would there have been for the Incarnation if there had never been a Fall?
I'm not sure what you think my reasoning is, but you are making my point. There would have been no reason for the Incarnation, or any of the rest of it. The actual result then, must make God a failure under your view. God created an immortal, sinless (by nature) being, and yet look what happened to His creation. Does God need more practice? Should He have taken a Mulligan? My question was aimed at whether it was possible (out of God's control) or only subject to God's ordination (God is in control). I take it that your side is with the former.
"I'm not sure what you think my reasoning is, but you are making my point. There would have been no reason for the Incarnation, or any of the rest of it."
Why do you think it would have been a bad thing if sin had never entered the world?
"The actual result then, must make God a failure under your view."
Not at all. Man was the author of his own Fall by the exercise of the free will he possessed.
"My question was aimed at whether it was possible (out of God's control) or only subject to God's ordination (God is in control). I take it that your side is with the former."
God chooses to let us exercise our free will. God has control of everything to the extent He chooses to use it. God created us for theosis, but he endowed us with free will, the same independence of action He possesses. We are created in the image and likeness of God and free will is an attribute of that. We have used it wrongly. Here's what +Athanasius says in On the Incarnation:
"Upon them, therefore, upon men who, as animals, were essentially impermanent, He bestowed a grace which other creatures lacked—namely the impress of His own Image, a share in the reasonable being of the very Word Himself, so that, reflecting Him and themselves becoming reasonable and expressing the Mind of God even as He does, though in limited degree they might continue for ever in the blessed and only true life of the saints in paradise. But since the will of man could turn either way, God secured this grace that He had given by making it conditional from the first upon two things—namely, a law and a place. He set them in His own paradise, and laid upon them a single prohibition. If they guarded the grace and retained the loveliness of their original innocence, then the life of paradise should be theirs, without sorrow, pain or care, and after it the assurance of immortality in heaven. But if they went astray and became vile, throwing away their birthright of beauty, then they would come under the natural law of death and live no longer in paradise, but, dying outside of it, continue in death and in corruption...This, then, was the plight of men. God had not only made them out of nothing, but had also graciously bestowed on them His own life by the grace of the Word. Then, turning from eternal things to things corruptible, by counsel of the devil, they had become the cause of their own corruption in death; for, as I said before, though they were by nature subject to corruption, the grace of their union with the Word made them capable of escaping from the natural law, provided that they retained the beauty of innocence with which they were created. That is to say, the presence of the Word with them shielded them even from natural corruption, as also Wisdom says: God created man for incorruption and as an image of His own eternity; but by envy of the devil death entered into the world." When this happened, men began to die, and corruption ran riot among them and held sway over them to an even more than natural degree, because it was the penalty of which God had forewarned them for transgressing the commandment. Indeed, they had in their sinning surpassed all limits; for, having invented wickedness in the beginning and so involved themselves in death and corruption, they had gone on gradually from bad to worse, not stopping at any one kind of evil, but continually, as with insatiable appetite, devising new kinds of sins."
Because of this state of affairs, FK, the Word became flesh and dwelt among us. Not because God failed but because we did and He loves His creation. Some posts back I suggested you read +Athanasius "On the Incarnation". It really explains what The Church believes and always has. If you read it, it becomes readily apparent why the Incarnation is the ultimate example of God's love for His creatures, but it is also apparent that but for our sin, the Incarnation would have been quite unnecessary and what the Incarnation does is return us to our original potential.