I wrote below to the effect that the uniform perfection of humanity consists in the multiform perfection of individual humans, that my perfection is not your perfection, and that each of our perfections lies in becoming what God wills us to be.
All this does raise some difficulties. For example, if my perfection is not your perfection, what is my perfection? What standard should we aim for, and how do we know, if each of us is aiming for a different standard?
The Christian impulse is to answer, "Jesus is the standard," then figure out what that means. But if the Christian impulse is correct here, then Jesus is the standard for all of us, which seems to mean the perfection of individual humans is uniform. And if the Christian impulse is not correct, then what are we to make of the Christian doctrine that we are to conform ourselves to Jesus. For that matter, isn't Jesus the perfect human, so that no one else who is perfect can be unlike Him?
I think these difficulties can be resolved by appealing to the original thesis. First, if each individual's perfection lies in becoming what God wills him to be, then Jesus is "the perfect human," and the standard of perfection for us all, because in His humanity He perfectly was what God willed Him to be. Again, that is what human perfection is; not this or that particular perfection, a certain standard of physical or mental ability, but to be what God wills us to be. "Son though He was, He learned obedience from what he suffered; and when He was made perfect, He became the source of eternal salvation for all who obey him, declared by God high priest according to the order of Melchizedek."
(A side note: In His humanity, Jesus had two perfections (says I). First, He was perfect at every moment of His life, doing His Father's will. Second, He
became perfect by completing His Father's will for His life. As a time-bound human, Jesus could not instantly be what the Father willed Him to be. Though He was our Savior from the moment of His conception, He didn't effectively become our Savior until His death and resurrection, if you see what I mean.)
So we can see Jesus as the single standard of human perfection, where that perfection is obedience to the will of the Father. Every perfect human would be identical to Jesus only if the Father wills that every human be identical to Jesus. But we can't be identical to Jesus. He, recall, is God. We are to be divinized, perhaps, but we will remain children by adoption. We simply can't become children by nature, so we simply can't become identical to Jesus.
That doesn't mean we have nothing to learn from the human standard Jesus sets other than obedience to the Father (although if we learned that perfectly, it would suffice). There remains the fact that we all share a common human nature; in terms of the thesis, this means that though God wills different things for each of us, He wills some things for all of us.
This is where the whole Christian moral tradition comes in. God wills that everyone love Him with all their heart, mind, soul, and strength, and their neighbor as themselves. God wills that we all have perfect faith and hope in Him. These are the universal human perfections, the things in which, the closer we are to Jesus, the closer we are to our own individual perfection.
We don't need to be itinerant First Century Jewish rabbis from Galilee to perfect ourselves. The Father doesn't want copies of His Eternal Son, He wants brothers and sisters for Him. We become Jesus' brothers and sisters by letting Him live in us, so that we share His universal perfections, but we become perfected as His brothers and sisters by achieving our individual perfections.
But why is the perfection of humanity multiform? Clearly it needs to be multiform in the present, since corporeal limitations prevent us from all being identical, but what does it buy us in eternity? And what does it buy God, the One who really does have everything? Sounds like there's one more post to be written on this.