From the solid declaration of the FOC
20] Dr. Luther has also more amply expounded and confirmed this opinion from God’s Word in the Large Catechism, where it is written: What, then, is the Sacrament of the Altar? Answer: It is the true body and blood of our Lord Jesus Christ, in and under the bread and wine, which we Christians are commanded by the Word of Christ to eat and to drink. 21] And shortly after: It is the ‘Word,’ I say, which makes and distinguishes this Sacrament, so that it is not mere bread and wine, but is, and is called. the body and blood of Christ. 22] Again: With this Word you can strengthen your conscience and say: If a hundred thousand devils, together with all fanatics, should rush forward, crying, How can bread and wine be the body and blood of Christ? I know that all spirits and scholars together are not as wise as is the Divine Majesty in His little finger. Now, here stands the Word of Christ: “Take, eat; this is My body. Drink ye all of this; this is the new testament in My blood,” etc. Here we abide, and would like to see those who will constitute themselves His masters, and make it different from what He has spoken.
35] For the reason why, in addition to the expressions of Christ and St. Paul (the bread in the Supper is the body of Christ or the communion of the body of Christ), also the forms: under the bread, with the bread, in the bread [the body of Christ is present and offered], are employed, is that by means of them the papistical transubstantiation may be rejected and the sacramental union of the unchanged essence of the bread and of the body of Christ indicated; 36] just as the expression, Verbum caro factum est, The Word was made flesh John 1:14 ], is repeated and explained by the equivalent expressions: The Word dwelt among us; likewise Col 2:9 ]: In Him dwelleth all the fulness of the Godhead bodily; likewise Acts 10:38 ]: God was with Him; likewise 2 Cor. 5:19 ]: God was in Christ, and the like; namely, that the divine essence is not changed into the human nature, but the two natures, unchanged, are personally united. [These phrases repeat and declare the expression of John, above mentioned, namely, that by the incarnation the divine essence is not changed into the human nature, but that the two natures without confusion are personally united.] 37] Even as many eminent ancient teachers, Justin, Cyprian, Augustine, Leo, Gelasius, Chrysostom and others, use this simile concerning the words of Christ’s testament: This is My body, that just as in Christ two distinct, unchanged natures are inseparably united, so in the Holy Supper the two substances, the natural bread and the true natural body of Christ, are present together here upon earth in the appointed administration of the Sacrament. 38] Although this union of the body and blood of Christ with the bread and wine is not a personal union, as that of the two natures in Christ, but as Dr. Luther and our theologians, in the frequently mentioned Articles of Agreement [Formula of Concord] in the year 1536 and in other places call it sacramentatem unionem, that is, a sacramental union, by which they wish to indicate that, although they also employ the formas: in pane, sub pane, cum pane, that is, these distinctive modes of speech: in the bread, under the bread, with the bread, yet they have received the words of Christ properly and as they read, and have understood the proposition, that is, the words of Christ’s testament: Hoc est corpus meum, This is My body, not as a figuratam propositionem, but inusitatam (that is, not as a figurative, allegorical expression or comment, but as an unusual expression). 39] For thus Justin says: This we receive not as common bread and common drink; but as Jesus Christ, our Savior, through the Word of God became flesh, and on account of our salvation also had flesh and blood, so we believe that the food blessed by Him through the Word and prayer is the body and blood of our Lord Jesus Christ. 40] Likewise Dr. Luther also in his Large and especially in his last Confession concerning the Lord’s Supper with great earnestness and zeal defends the very form of expression which Christ used at the first Supper.
This is what I mean by dogmatism. That we use metaphysical terms in the affirmative because they give use a framework of language so that we may know what we are talking about, but it is the fine points of meaning in the words about which is the controversy.