Because animals don't have spirit, so addition of spirit isn't fusion. Imagine the master of the dog is dissapointed and incarnates himself in a dog. What kind of example will he be for other dogs, if he just animates the soulless body of dog and be faithful to the master?
That's precisely the point. How on earth will a dog really know humanity unless humanity stoops to the level of the dog?
With Christ, this is complicated - we have our own soul, our own awareness and personality. Even if fusion with Divine occurs, we can't lose it. Thus were did Christ's human soul/personality go after crucifixion or ressurection? It can't get fused with God and become one with God the Word. As Theodoret says - divine is immutable, there is no fusion or confusion.
I don't mean "fusion" as confusion. I mean a very real unity. If a human was incarnate into a dog form, wouldn't you direct the dog senses and mind towards human means? This is what the Word of God did. In becoming man, He directed humanity, all of it, towards divine means. It is partaking of the divinity with full knowledge, full desire, full human instinct. If Christ didn't have a human soul, then the incarnation means nothing for us.
Second of all, the being of animal is at a much lower level than the being of a man. You can call that being "person." Nevertheless, because animals don't have spirits do not mean they're not "persons." They are, albeit in a different level.
When you are conflicted between human persona and divine persona, you are equating both of them, and not realizing that the divine "person" is at a level of which we cannot understand. So He came to us at a level that we can understand.
In any case, if Divine Word got fused with human soul of Jesus, that still means he animated one of the humans to achieve this and we get into Nestorian fallacy.
He didn't animate "one of the humans." He was formed and born from the womb of the Theotokos. From the very moment of His human existence, the Word of God partook of it and became it. There was no adoptionism.
So why is it written: "as he was tempted fully, he is helper for others who are also being tempted"(Hebrews 2:18) - if he was impotent of sinning, how was it possible to tempt him?
I just explained to you how He is a helper to those who are tempted. Read what I wrote again. Temptation is not sinning. It's temptation. Two different things. He destroyed temptation and with it destroyed sin. That's the point. And when He does this, He promises us the same when we are in communion with Him.
If I am impotent and never have sexual urges, will I ever be example to others if I stay virgin my whole life?
Why would you assume a person who does not have sexual urges "impotent"? Those are two different things. And yes, it's very important that a person who does not have sexual urges be the fulcrum of my need to lay off sexual urges. If I am blind, I want someone who can see to lead me to the right path, not someone else who's blind.
But what differentiates human reasoning from divine reasoning?
Even in reasoning, there's a HUGE CHASM. Human reasoning is nothing compared to divine reasoning. That's the whole point of this conversation that I've been trying to tell you.
I have divine reasoning if I want to be sinless, obey God, have love and etc.
No, you do not have divine reasoning. You have human reasoning, and you seek divine inspiration. Big difference. If you say you have divine reasoning, you say you are God.
Although my flesh has urges and if I don't have enough strength of will, I will fail. That's why I say, it's the urges that may sin and not the mind.
Your urges are weaknesses of your marred will. It's like being blind. You spiritual blindness will lead you to fail more and more. You need someone who can see to lead you away from failure.
That's why I say, that for Christ, assuming human soul with human mind wasn't necessary.
Since your arguments before that fail, it shows how necessary it is for Christ to have assumed a human mind.
Although there is only one big issue here - We don't have the amount of faith we needed, as Christ said to Apostles, or else we could have lifted mountains. This is what differentiates human soul from the divine minded soul.
Faith is putting all your trust and belief in God. It has nothing to do with what type of soul one has. A dog has faith in his master and will do the craziest things for him, and yet the dog is not even human.
I am kind of Pelagianist and say that we don't have sinful nature and we can achieve sinlessness from our nature and personal will, with the help of God(divine sinergy) in case of Christians. Although I believe that the non-Christian can also be sinless, because sin is transgression of law, and not faithlessness(which is obligatory nevertheless)
Pelagianism is the belief that one can be sinless WITHOUT God. But if one seeks God's help, then that means one can't be sinless alone, and that's Orthodox.
I can't explain incarnation any other way. There can't be fusion. And if there was human soul, that soul should have had thoughts which are considered sin too, or else Word of God was controlling those thoughts too, and it's obscure how can we achieve what Incarnated Christ has achieved.
It's obscure because you're not at His level, i.e. you're not God. He came to your level to lift you up, not to struggle in human means. He came for us, not for Himself. So taking full humanity is an obscure thing in and of itself, and we have to acknowledge that, and we also have to acknowledge why He came. It's not for Him to struggle, but He endured human temptation, suffering, and death, and rose from it all for us to struggle in Him.