The fundamental truth of the incarnation is that the human man, Jesus of Nazareth belongs to the eternal identity of God as the Son of the Father. This means that everything that Jesus is is part of the eternal Triune life. If we say that the incarnation is something that only takes place because of some contingent events in history (the fall), then God’s very being is made contingent upon human action.
In other words, if Jesus really is the Trinitarian Son and if the Trinitarian Son’s becoming incarnate as Jesus is just a band-aid fix for repairing human sin, then the incarnation introduces a radical change into the being of God, such that God becomes what he was not before, and thus Jesus is not as such the Logos, rather the Logos somehow subsists ‘in’ Jesus, but is not, strictly speaking identical with Jesus. It should not even need to be said that this is heretical. If Jesus of Nazareth is not exclusively and without remainder identical with the Son of God, then we are still in our sins.
However if Jesus simply is the Son of God – rather than some nonsense about the Logos subsisting ‘in’ Jesus – then Jesus’ incarnate humanity is eternally part of the Triune life. Thus, the Son is eternally incarnandus. This is not to deny that the Word became flesh in time. Rather it is to deny that something which has a temporal begining cannot also be eternal, for if the incarnation reveals anything it is that God’s Triune time is not incompatible with created time. The becoming flesh of the Word as (not in!) Jesus did indeed happen at a point in space and time. However, that event in space and time occured within the broader framework of the eternal Triune relations. The Trinitarian Son can become flesh in history because the eternal being of the Triune God is in becoming and that eternal becoming eternally includes his incarnation. The incarnation, on this reading does not introduce a “change” into the being of God, or rather the change that it introduces is but a ripple from a pebble within a mighty waterfall. God’s life is an ocean of overabundant becoming into which the incarnation is eternally and seamlessly enfolded.
Ultimately on this Christological issue we’re left with one of two choices: either the reality of the human Jesus is eternally included within the identity of God, or the incarnation is only a response to sin and therefore human sin radically changes the being of God into something different that who God has been eternally. With Irenaus, Barth, and von Balthasar I choose the former option. Jesus is the Logos. Period.