As I'm preparing to advocate and analyze a "high church" attitude and approach to the Liturgy at the ACELC conference in Austin, Texas, later this month, I'm presently working with the following hypothesis:
"High Church" Liturgy goes hand-in-hand with a high Christology, which believes, teaches, and confesses that the Man Christ Jesus is the one true God; that St. Mary is the Mother of God, because the Son that she conceived in her womb and bore in her body is the Second Person of the Holy Trinity; and that it was, indeed, the Lord our God who was crucified, dead, and buried, under Pontius Pilate on Good Friday.
This high Christology recognizes, likewise, that Christ Jesus, the Son of the Living God, who is also true Man, crucified and risen from the dead, is actively present and at work in the Liturgy; that He is, in fact, the true and divine Liturgist, who speaks, does, and gives Himself and all good things to us by His preaching of the Gospel and His administration of the Sacraments in the Divine Service. He is acknowledged and adored in the earthly and external means by which He serves His Church, because we affirm and confess the unity of His two natures in His one Person, even as He deals with us through humble instruments under the Cross.
A high view of Christ also affords a high regard for His Bride, the Church, who is adorned with His righteousness and holiness, His innocence and blessedness, His beauty and His grace.
It seems to me, at any rate, that a "high church" attitude and approach to the Liturgy has far more to do with Christology, first and foremost, before it has anything to do with ceremony. Although it is meet, right, and salutary that appropriate bodily ceremonies should accompany and adorn the verbal confession of Christ, in practice, those ceremonies will differ in various ways from place to place, and from time to time; whereas Christ our Lord remains constant at all times and in all places, and so should our Christology.
In brief, I would describe a "high church" Christology as typically Alexandrian, following in the footsteps of Athanasius, Cyril, Aquinas, Luther, and Chemnitz.
In contrast to this "high church" attitude and approach, I would offer that a typical "middle-of-the-road" approach, in practice, adopts a more Antiochene Christology with respect to the life of the Church in the Divine Service. By that I mean that there is a comparatively greater emphasis on the history of Christ's life, on the explanation of what He has done and taught in the past, and on the "humanity" of the minister and the means of grace, than on the active presence of the incarnate Son of God in the Office of the Holy Ministry, in the preaching and administration of the Gospel, and in the consecrated elements of the Sacrament.