Read Pr Matthew Harrison's paper, Liturgical Uniformity and Church Polity in the Augsburg Confession and the Formula of Concord: the Church Orders as Hermeneutical Key (pdf, 13 pages, 228 KB; printable pdf, 8 pages, 106 KB), which was published in Lutheran Theological Journal, Vol 36, No 2 (2002), pp. 71-83.