Athanasius, On the Incarnation. This has to be # 1 on your list. Athanasius’ classic work on the incarnation, shows the relationship of incarnation to God’s purposes, creation, atonement, and more. Check out Brandon Smith and Luke Stamps discussing this book on the Church Grammar podcast.
Athanasius, Orations of St. Athanasius Against the Arians. Athanasius throws some polemical shade on the Arians, questioning their exegesis of key biblical texts like Prov. 8.22-23 and Col. 1.15, and trying to shatter their whole christological project.
Augustine, Sermon 191. Augustine’s famous Christmas sermon about the Word made flesh: “Christ, the only-begotten Son of God, the true Sun of Justice, so shone upon the earth as not to leave the heavens, remaining there eternally, but coming hither for a time; there determining the everlasting day, here enduring the day of humanity; there living perpetually without the passage of time, here dying in time without the inroads of sin; there remaining in life without end, here freeing our life from the destruction of death.”
Anselm, Cur Deus Homo. Another classic work by the eleventh-century Archbishop of Canterbury. Tackles incarnation and atonement simultaneously.
Friedrich Schleiermacher, Christmas Eve: Dialogue on the Incarnation. This is the classic old liberal view of the incarnation where Schleiermacher tries to restate the meaning of incarnation for a post-Kantian world.
Karl Barth, Church Dogmatics, I/2. This could be considered a rejoinder to Schleiermacher in many ways. Barth’s section on “The Miracle of Christmas” is one of the best parts of his entire Church Dogmatics. Bromiley summarizes Barth this way: “‘Incarnation of the Word’ asserts the presence of God in our World and as a member of this world, as a Man among men. It is thus God’s revelation to us, and our reconciliation with Him. That this revelation and reconciliation have already taken place is the content of the Christmas message.”
Thomas F. Torrance, Incarnation: The Person and Life of Christ. Torrance was a top Scottish theologian with Barthian sympathies and this is his celebrated study of the incarnation.
Sarah Coakley, Why the Incarnation? Okay, this is not a book, but an interesting and thought-provoking video-interview with Coakley about the incarnation. Very informative and a good discussion by a leading modern theologian.
Graham Cole, The God Who Became Human. Okay, this is my go-to book and the one I’d assign to students. A great mix of biblical exposition and historical theology, all done with the heart of a pastor.
Ian McFarland, The Word Made Flesh: A Theology of the Incarnation. I’ve not read this, it is a recent publication, but I’ve heard it is an interesting book, especially its “incarnation anyway” argument.
Thanks! These are definitely going on my list. I definitely want to read the more ancient stuff like Athanasius & Augustine on this.