I am a subscriber to the Lutheran liturgical quarterly Gottesdienst, which I recommend to all. The journal's epigram is Leitourgia Divina adiaphora non est, which translates to "The Divine Liturgy is not indifferent things." The journal's editors explain this aphorism as follows:
The principle expressed here is that the historic Divine Service of the Western Christian Church is more than Christian antiquity. It is a theological treasure which can and should be used in today's Christian Church. It has well served our Mother Church and our fathers in the faith for the past centuries and there is no reason to believe that it will not continue to do so in the future.
This is a sentiment with which I entirely concur. But the editors have not quite shown that the liturgy is not an adiaphoron. It is my understanding that "adiaphoron," in Lutheran theology, is a technical term with a precise definition: a practice neither commanded nor forbidden by God in Holy Scripture, which may therefore may neither be required nor prohibited in the Church. Thus to claim that something is not an adiaphoron is to claim that it is indeed commanded by God in Holy Scripture.
The editors are aware of this; for they go on to say:
Moreover, to say that liturgy is something not commanded by God is to reject the clear words of our Lord, who indeed has given specific commands which are quite liturgical in nature; for example, This do, pertaining to the Sacrament, and When ye pray, say, pertaining to the Our Father.
It is true that the Scriptures provide some instructions of a liturgical nature, such as the examples just cited. But to say that the liturgical instructions contained in the New Testament are sketchy would be something of an understatement. All of the liturgical instructions in the New Testament, taken together, fall very far short of even a minimal liturgical ordo. For example, the Lord does tell us "This do in remembrance of Me," but there is no indication that it is necessary to make that remembrance in the liturgical assembly. If I should decide to celebrate the Lord's Supper at my kitchen table with my family (or even by myself alone), there is nothing in Scripture that forbids me to do so.
It would seem that by the strict definition of an adiaphoron, the elements of the liturgy which are truly not adiaphora (because they have an explicit Scriptural command) form a very small subset of the Church's traditional liturgical praxis; and by trying to include all of the historic Divine Service of the Western Christian Church as non-adiaphora by reference to the fact that a small subset of it has divine sanction, the Gottesdienst editors are stealing a base.
I have a twofold question for my fellow Lutherans: are the Gottesdienst editors right to claim that the Church's liturgical ordo is not an adiaphoron? and if so, is that consistent with a properly Lutheran understanding of Sola Scriptura? (Non-Lutheran readers are certainly welcome to chime in as well, of course.)
My own view on this question can be found (implicitly, at least) in an earlier post here. Dix dixit.