Someone recently observed that I am significantly interested in adiaphora. It's true. Thinking about adiaphora has occupied much of my time and attention for the past decade or more, and that continues to be so; not only from a theoretical perspective, but with very practical consideration. Whatever isn't adiaphora should simply be acknowledged and honored as the will of God: What He has commanded should be done, and what He has forbidden should not be done. His Word, and His good gifts, especially of the Gospel, are definitive and of central importance. So, it's not as though I am not chiefly concerned with those things that are divinely given. But that which the Lord has left free requires thoughtful consideration, discernment and discretion, in order to guard the freedom for which He has set us free, and so also to use that precious freedom wisely and well.
The fact that God has given us the Gospel by His Word and Sacraments, that is, by external means, requires that adiaphora will be involved in the administration of the Gospel. The same particular adiaphora will not be necessary in every time and place, else they would not be adiaphora. However, some or other adiaphora will necessarily be employed in every case, because it is impossible to do what the Lord has commanded without doing many other things that He has left free and unspecified. There will always be choices and decisions to be made in this respect, whether deliberately or haphazardly.
In considering those choices and decisions having to do with adiaphora, I have recently begun to realize that several or more different questions are involved. That doesn't seem all that striking or significant, except that, where those different questions are not distinguished, the conversation easily becomes muddled. The answer to one question may seem to be addressing a different question altogether, when it really does not. If I'm simply discussing the merits or demerits of a particular practice, but someone perceives that I am presuming to impose my own opinion on the Church, that presents a false impression that is helpful to no one. If someone else is proposing a way for the Church collectively to make decisions and order her life accordingly, but that is heard as though righteousness were thereby to be gained, that would be a grossly unfortunate misunderstanding.
So, I have been thinking about the several or more different questions that need to be asked and answered with respect to adiaphora:
First, there is the question of actually defining and identifying what are and are not adiaphora. It seems like that ought to be simple enough, and in many cases it surely is. But not always. Reverence is required, whereas frivolity and irreverence are forbidden, but defining and identifying "reverence" vs. "irreverence" is a difficult task. Likewise, the Holy Scriptures frequently commend "beauty," but how is that to be discerned?
Second, there is the question of the criteria by which adiaphora will be measured and evaluated. All things are lawful, but not all things are edifying or profitable. With respect to the clarity of catechesis and confession, a spectrum of adiaphora may be considered and compared, in order to identify better and stronger practices, on the one hand, and to rule out those practices that are ambiguous and unhelpful.
Third, there is the question of where and how the practical decisions of adiaphora will actually be made: By the individual Christian, by the local pastor and/or the local congregation, by a fellowship of congregations in a particular territory, or by as large a representation of the Church as possible? There are variously matters of personal piety, of local custom, of confessional identity, and of ecumenical tradition to be considered. Not all of the decisions regarding adiaphora will be made at the same level, nor in the same way, nor with the same significance. The Nicene Creed, for example, is neither commanded nor forbidden by God, but it is not free in the same way or to the same extent that ecclesiastical art and architecture are.
Fourth, there is the question of the benefit, importance, and value of uniformity in adiaphora within the fellowship of the Church. This question is closely related to the previous one, but it goes beyond asking where and how decisions will be made. It addresses the implementation of common practices across a community of congregations. If that is not to be done arbitrarily or legalistically, but in active love for Christ and His Church, it needs to be understood what uniformity in adiaphora is, what it includes, what it does, and what it means. Then uniformity will not be a denial of freedom, but a godly exercise of freedom.
There are further ways of parsing these different questions, and they could be subdivided considerably. As particulars are explored, numerous questions of detail emerge, along with questions of polity, structure and governance, pastoral authority and care, and dealing with exceptional circumstances as they emerge. Yet, it seems to me that identifying these several or more different questions provides some clarity for conversation.