The following is from the Church Order for Braunschweig-Wolfenbüttel by Martin Chemnitz and Jacob Andreae from 1569.   Note how these future authors of the Formula of Concord deal with adiaphora and ceremonies (extolling what they do) and especially how they are unafraid to direct neighboring churches to have as much uniformity as possible in such ceremonies and to command pastors to strictly abide by the Evangelical Lutheran Order of the land.  

The people shall be instructed, as Paul teaches in 1 Corinthians 14 [:40], that it is God’s will that, when the congregation gathers together for the administration of the Word, Sacraments and prayers, all things are to be done and observed with good decency, in order, and for the building up. And therefore the churches of the Reformation have and retain certain free, adiaphorous ceremonies, not with an understanding like that of the pope, who has forced his precepts upon the church, as mentioned above, but only to the end that in such assemblies everything may be done decently, in order, and for building up:  that there may be one certain order where, when, by whom, and in what form and manner the administration of the Word, Sacraments, and prayers will be held, what should come first, what should follow after; and that there may be such ceremonies as give external indication that great exalted, serious things are happening in the congregation, so that the ceremonies may serve as guidance, incitement, admonition, and stimulus, that the people may concentrate their thoughts and lift up their hearts in all humility, so that with sincere devotion they may dispose themselves to the Word, Sacrament, and prayer in the congregation.  For this is what Paul means when he says that, in such assemblies, all things are to be done with good decency, in order, and for building up.

Therefore, the people shall frequently be exhorted to love such gatherings of the church of God, because there God desires to be present, to work through Word and Sacraments, and to give His grace to believers.  They should also enjoy attending these ceremonies before and after the sermon and use them to the end here stated.  

And though Christians are not everywhere bound to the same specific ceremonies- for Christian freedom has its place in this article, as the ancients say, “Dissonance in rites does not harm consonance in faith”- nevertheless, because there is still all manner of benefit inherent in keeping ceremonies as uniform as possible, and because this also serves to maintain unity in doctrine, also because common, simple, weak consciences are all the les offended and rather the more improved, it is therefore viewed as good that, as much as possible, uniformity in ceremonies with the neighboring Reformation churches should be achieved and maintained.  And for this reason, in the matter of ceremonies, all pastors in the churches of our principality shall henceforth strictly abide by and conform to the order described below, and it shall not be neglected without exceptional and considerable cause.

Additionally, the common people may nevertheless be instructed regarding such ceremonies, how they are a matter of Christian freedom and to what end they are observed and used, lest the old papistic delusion become attached to ceremonies once more.  (Chemnitz’s Works, Vol. 9. Trans. by J Corzine, MC Harrison, and A Smith. Ed. By J Corzine and M Carver, CPH, 2015, pp. 78-79.)