The "second Martin," Martin Chemnitz, one of the chief architects of the Formula of Concord and Book of Concord, wrote what remains to this day the definitive Orthdodox Lutheran discussion of Christology in his masterful work The Two Natures in Christ. I was particularly struck today by the powerful comfort that is ours because of the blessed Incarnation of our Lord and the Personal Union of the Divine and human nature. When we speak of the presence of Christ among us today, we are not playing a word game, or make- believe. His presence among us is a reality, in the Word and Sacraments. Chemnitz had this to say in response to those who try to throw up road blocks to His presence in the Supper.

"When in opposition to the presence of Christ in the Supper they raise
the matter of locations, distances, intervals, and separations of
places, we correctly reply that since all things have been placed in
subjection under Christ’s feet, also according to His assumed human
nature, so that He has all things in His hands and under His dominion
and rules all things with authority, and since there is no exception
made for intervals or spatial interruptions, with the exception only of
the One who has all things in subjection to Himself, how then can we
say with a clear conscience that intervals of space prevent or impede
the Son of God from being able to be present with His body in the
Supper, as the words of His testament declare, since He has both space,
time, and all things powerfully in His hands and under His feet, also
according to His human nature?

"He is not present locally, however, and at the right hand of God, except by the divine power of the personal union. For the assumed nature of Christ, as we have said before, exists personally in close presence in the hypostasis [union of the two natures] of the Son of God which in turn also exists in all places and above and beyond all places, and has the assumed nature united with Himself in a close, intimate, and undivided presence.

"Therefore in His pure Word He has given and promised the church that, with His true nature unimpaired, He can be present with it beyond every localization where He wills to be present. [Matt. 28:20] Thus, when we begin with the Word and promise concerning the presence of Christ’s body and against all objection add His divine power, the personal union, and His session at the right hand to His will as it is revealed in the Word, it is surely manifest that the Son of God can accomplish what He teaches and promises in His Word concerning His body, while still leaving its true reality intact; so that with His body He can be present when, how, and wherever He wishes. And we can judge from the Word concerning His will. For since we have the Word, there is no reason that we should reject it on the grounds of the essential or natural qualities of the body. For in the preceding chapters we have shown to what prerogatives and honors the assumed nature in Christ has been exalted by the personal union. And now we must reply to those arguments which are usually raised. But first let us complete our treatment of the presence of Christ in the church. Up to this point we have talked about the Lord’s Supper.

"Fourth, not only at that place and at that moment when and where the Lord’s Supper is celebrated in a public service of the church, however, is the whole Christ in both natures present with His church militant on earth, as if as soon as the celebration of the Supper is completed He removes His presence, or as if, in the words of the gloss on the Decrees, He were to fly away into heaven, and the members of the church, outside the public service, in their work, in their temptations and tribulations would be deprived of the comforting presence of Christ, their High Priest, their King, their Head, and their Brother. For in the action of the Lord’s Supper there is a public, solemn, and peculiar witness and seal that Christ, our Mediator and Savior, wills to be graciously present with His church in its struggle here on earth, not with only one portion and part of Himself, that is, with only His deity, but wholly and completely, that is, with His assumed nature also, by which He is of the same substance with and related to us, our Brother. For in this nature He was tempted, so that He could share in our wretchedness; in this nature He accomplished by His suffering and death the work of our redemption, so that we thus might be made members of His body, of His blood, and of His bones. Because our reason and sense do not understand or comprehend this, therefore Paul says, “Great is this mystery in Christ and in His church.” (Eph. 5:32)

"I therefore distinguish also between these kinds of presence: in the first place He walked on earth, in the second He appears in heaven in glory, in the third He is present in the Supper with the bread and wine, in the fourth He is present in the whole church, and in the fifth He has all creatures present with Him in a sense (ἐν λόγῳ)."

Source:

Martin Chemnitz, The Two Natures in Christ, Trans. by J.A.O. Preus (Saint Louis: Concordia Publishing House, 1971), p. 447.