Irenaeus, one of my favorite of the early church fathers, wrote in Against Heresies, IV 33:4 "How shall man pass into God unless God pass into man..."
Wow! With these few words Irenaeus moves the heart of the Incarnation and its place within God's great plan of salvation. To those who play with the Virgin Birth as if it were somehow a trivial matter, to those who wince at the careful distinctions of words within the creed, to those who treat the flesh of Jesus Christ as somehow unrelated to His mission and purpose, these words cut to the heart of it all. We have no hope of passing into God (of being reconciled to our Creator and to our place within His creation) unless God pass into our flesh and blood (the incomprehensible but essential Christian truth of God incarnate).
It is weeks after Christmass but we cannot venture far from Bethlehem. The Incarnation of our Lord is the fulcrum that holds our hope of salvation in balance. I find that Lutherans tend to be more "incarnational" in our thinking than some other Christians. This is a good thing. We see the Eucharist in incarnational terms (Jesus being fully human and divine yet one person... bread and Body, wine and Blood each fully authentic yet one sacramental element and gift).
If we are to long for the redemption of our lost lives and if we are to hope for the restoration of our place as sons within the family of our Father, it rests upon the fact and truth of Jesus Christ incarnate (en-fleshed). It is this incarnational reality that bridges the gap between God and creation, God and humanity. It is this incarnational miracle that holds forth the hope and promise of the miracle of our own redemption and life with God.
And it is connected to baptism. The Baptism of our Lord is where we see visually what it means for our Lord to pass into man, our place as men under the Law, in this world of sin, and living under the shadow of death. Our own baptism into Christ is where we see visually what it means for us to be born anew, for the old to pass away and the new come forth from the water, man passing into God -- sacramentally in baptism, living out this life in faith, until the completion of what Christ began is consummated by His return in glory.
Irenaeus is one of the great pillars of the Church and book 4 of His treatise Against Heresies is probably his premier writing. Would that we all could write and speak with such economic yet language about what happened when the Angel spoke to Mary and Mary and Joseph made their way to Bethlehem!!
We have got to get away from the idea that the Incarnation was God's plan B when the plan A of the commandments failed to accomplish their purpose. This simplistic and distorted sense of things has crippled the Church and individual Christians along the way. Clearly and without doubt, Christ and His incarnation is the one and only plan of God, the one and only means to bringing man back into communion with the Father and into His destined place as a sharer in the Divine life.