Flamme, A Small Catechsim on the Divine Call (https://wolfmueller.co/a-small-catechism-on-the-divine-call/)
Luther, “Infiltrating and Clandestine Preachers,” AE 40:
For the Holy Spirit does not come with stealth. He descends in full view from heaven. The serpents glide unnoticed. The doves fly. You can be sure that this secretiveness is characteristic of the devil.
If we did not hold fast to and emphasize the call and commission, there would finally be no church.
When God does not do so we are to remain obedient to the office and authority already ordained. If the incumbents of the office teach wrongly, what affair is that of yours? You are not called to give account for it.
Luther, Sermons on John, 3.34: "There are two ways of sending. First, God sent his messengers, the prophets and apostles, like Moses and St. Paul, directly and without the help of an intermediary. These men were called by God's word of mouth and without human agency. Such sending was done only when God wished to inaugurate something new, as was the case when He sent Moses and the prophets. This exalted method came to an end in the New Testament with the apostles, who were the last to be called directly by God.
"The other way of sending is indeed also one by God, but it is done through the instrumentality of man. It has been employed ever since God established the ministry with its preaching and its exercise of the Office of the Keys. This ministry will endure and is not to be replaced by any other. But the incumbents of this ministry do not remain; they die. This necessitates an ever-new supply of preachers, which calls for the employment of certain means. The ministry, that is, the Word of God, Baptism, and Holy Communion, came directly from Christ; but later Christ departed from this earth. Now a new way of sending was instituted, which works through man but is not of man. We were sent according to this method; according to it, we elect and send others, and we install them in their ministry to preach and to administer the Sacraments. This type of sending is also of God and commanded by God. Even though God resorts to our aid and to human agency, it is he himself who sends laborers into His vineyard.
"Therefore everyone must realize that he has to be sent. That is, he must know that he has been called; he dare not venture to sneak into the office furtively and without authorization. It must be done in the open. The sending is done through man, for example, when a city, a prince, or a congregation calls someone into office. But at the same time this person is sent by God."
Chemnitz, Loci, 700-1: And that those who are lawfully called in this way through regular means have been called and sent by God Himself, can be clearly proved from Scripture. Timothy was called not directly but through Paul and the presbytery, as we have just now said, 1 Tim. 4:14 and 2 Tim. 1:6, and he had a charge to ordain other presbyters, 2 Tim. 2:2. Yet Paul in Acts 20:28 says to all the presbyters of the church of Ephesus, “The Holy Spirit has made you overseers, to lead the church of God, which He has purchased with His own blood.” And in 2 Cor. 5:18–20, an epistle to which Timothy also added his name, 1:1, Paul says not only of himself name but in the plural, “God has given to us the ministry of reconciliation. Therefore we are ambassadors in the name of Christ, with God appealing through us.” In 1 Cor. 12:28, therefore, Paul says, “God has appointed in the church not only apostles,” who were immediately called, but also “teachers,” who are mediately called.