Luther says, in The Smalcald Articles:
“The church cannot be better ruled and preserved than if we all live under one head, Christ, and all the bishops—equal according to the office (although they may be unequal in their gifts)—keep diligently together in unity of teaching, faith, sacraments, prayers, and works of love, etc.” (Part II. The Fourth Article, 9).
Melanchthon clarifies, in the Treatise on the Power and Primacy of the Pope, with these points:
+ The gospel bestows upon those who preside over the churches the commission to proclaim the gospel, forgive sins, and administer the sacraments. In addition, it bestows legal authority, that is, the charge to excommunicate those whose crimes are public knowledge and to absolve those who repent .
+ This power is shared by divine right by all who preside in the churches, whether they are called pastors, presbyters, or bishops .
+ In the apostolic letters all who preside over churches are both bishops and presbyters .
+The distinctions of degree between bishop and presbyter or pastor are established by human authority  (cf. Apology XIV: Church Order, 1).
Therefore, this is our church polity: Pastors preside (oversee, serve as bishops) in the churches by divine authority, and they do so as equals in matters between congregations for mutual accountability.