The incarnation is once for all, but it isn’t a special characteristic or element in the Divinity which incarnates, but rather the very center of the Divinity. In order to make this problem clear, the Logos concept was used. The problem was to combine monotheism, which was emphasized so strongly against pagan polytheism, with the divinity of Christ – the humanity and the universality of His nature at the same time. This was the need for that time. The Apologists fulfilled that need and therefore they were successful.
Now the incarnation itself, in the Apologists, is not the union of the Divine Spirit with the man Jesus, but the Logos really becomes man. This transformation Christology becomes more and more important through the Logos doctrine.
Existing before the Logos, He now, through the will of God, has become man. He has been made f lesh, as Justin says.
This is the first clear decision for the transformation Christology over against the adoptionist Christology. If the Logos or the Spirit adopted the man Jesus, then we have a quite different Christology from the idea that the Logos is made, is transformed into, flesh.
Now I leave all this open. I hope you have many questions and many shakings of your heads about this, because it is certainly not easy, since the concept of Logos is for us not what it was for every reader of Justin among the educated pagans. We know God and we know man, but the idea of hypostasis, of powers of being in God, is extremely difficult for us. But this was the content of the old Christian Christology, and this is still present whenever we perform our liturgy, which all. are dependent on this Christology.
The saving gifts of the Logos are gnosis (knowledge) of God, of the law, and of the resurrection. Christ is, as Logos, as reason, first of all teacher, but not a teacher who teaches us a lot of things he knows better than we, but teacher in the Socratic sense, namely, in the sense of giving us existential power of being.