Fifth, the church is recognized externally by the fact that it consecrates or calls ministers, or has offices that it is to administer. There must be bishops, pastors, or preachers, who publicly and privately give, administer, and use the aforementioned four things or holy possessions [the Word, the Sacraments of Baptism and the Lord’s Supper, and the public exercise of the keys] in behalf of and in the name of the church, or rather by reason of their institution by Christ, as St. Paul states in Ephesians 4, “He received gifts among men, …” — his gifts were that some should be apostles, some prophets, some evangelists, some teachers and governors, etc. The people as a whole cannot do these things, but must entrust or have them entrusted to one person. … Wherever you see this done, be assured that God’s people, the holy Christian people, are present.
It is, however, true that the Holy Spirit has excepted women, children, and incompetent people from this function, but chooses (except in emergencies) only competent males to fill this office, as one reads here and there in the epistles of St. Paul that a bishop must be pious, able to teach, and the husband of one wife — and in 1 Corinthians 14 he says, “The women should keep silence in the churches.” In summary, it must be a competent and chosen man. …
Here the pope will object through his loudmouths and brawlers of the devil, saying, “St. Paul does not speak only of pastors and preachers [in Ephesians 4:11], but also of apostles, evangelists, prophets, and other high spiritual vocations; that is why there must be higher vocations in the church than those of pastors and preachers. What, Sir Luther, do you have to say now?” …
Now, if the apostles, evangelists, and prophets are no longer living, others must have replaced them and will replace them until the end of the world, for the church shall last until the end of the world [Mat. 28:20]. Apostles, evangelists, and prophets must therefore remain, no matter what their name, to promote God’s word and work. The pope and his followers, who persecute God’s word while admitting that it is true, must be very poor apostles, evangelists, and prophets, just like the devil and his angels. …
Just as was said earlier about the other four parts of the great, divine, holy possession by which the holy church is sanctified, that you need not care who or how those from whom you receive it are, so again you should not ask who and how he is who gives it to you or [who] has the office. For all of it is given, not to him who has the office, but to him who is to recieve it through this office, except that he can receive it together with you if he so desires. …
From Luther’s Works American Edition vol. 41, p. 154 ff, “On the Councils and the Church”