The Augsburg Confession
XIV. Order in the Church
It is taught among us that nobody should publicly teach or preach or administer the sacraments in the church without a regular call.
XV. Church Usages
1 With regard to church usages that have been established by men, it is taught among us that those usages are to be observed which may be observed without sin and which contribute to peace and good order in the church, among them being certain holy days, festivals, and the like.
2 Yet we accompany these observances with instruction so that consciences may not be burdened by the notion that such things are necessary for salvation.
3 Moreover it is taught that all ordinances and traditions instituted by men for the purpose of propitiating God and earning grace are contrary to the Gospel and the teaching about faith in Christ.
4 Accordingly monastic vows and other traditions concerning distinction of foods, days, etc., by which it is intended to earn grace and make satisfaction for sin, are useless and contrary to the Gospel.
The call to teach or preach or administer the sacraments is a holy vocation. It is one through which Christ delivers His forgiveness and His very self. Though the one called is just a man with no merit or worthiness in him, he is used nonetheless by Christ to speak absolution, setting sinners free from the bondage of sin, and to give the promise of salvation in the Lord’s Supper and the waters of Baptism. It is this Word of promise, the promise of the forgiveness of sins that is spoken by the minister in the stead or place of, and by the command of Christ. (Matthew 6:19 ESV). The minister does not have authority to forgive sins by himself, but he and the Church is given that authority by Christ. The minister is a tool that Christ uses to show mercy to the Church and to the whole world. Even though Christ has gone to prepare a place for us, He is still present through His Church, and through those who go in His stead to proclaim “liberty to the captives…,” (Luke 4:18) to forgive sins with the Gospel which is the “the power of God for salvation to everyone who believes” (Romans 1:16 ESV).
A “regular call” is simply an official, public and orderly call. This is to humble the minister as a servant of Christ, the Gospel, and the Church. It is also to protect the Gospel from corruption and the Church from harm. This eliminates a “mystical call” in which the “minister” believes he has authority in the Church apart from the Word of Christ and the call of the Church. No inner feeling or conviction will do for this true and regular call. It must come in accordance with the command of Christ and His Word (the Bible), and the public call of the church. Ordaining a minister, if you have heard that term used, is most simply a public installation, by the Church, of the called man into the office of minister. The apostles were chosen and publicly installed by Christ Himself, and these apostles have taught us to keep with the Word, the one true Gospel, and to follow their patterns in the ministry. This particular call and ordination is what distinguishes someone in the teaching, preaching, or administration office of the sacraments from the office that is held by the Priesthood of All Believers. Each believer is a Priest, and holds the authority of “the office of the keys” that Christ gave. The believer is tasked with the responsibility to forgive others, that they may be forgiven for eternity. The called and ordained minister differs in that he is called additionally to give this forgiveness publicly and regularly. This ensures that the church will receive it and that it is available to all.
So is the call to teach or preach or administer the sacraments a holier calling than other callings? It may be considered holier in the sense that the Gospel is more precious than anything in this world and God has set apart (made holy) some for the giving of this Gospel. Yet, it is not holier in the sense that the people who God calls are not any more holy than any other believer. In other words they are not called because they are better people. Also, it is a vocation like any other vocation. God uses people in the ministry vocation just as He uses mothers, Presidents, janitors and electricians. We see throughout Scripture that God uses sinful people in all walks of life from Kings to beggars, from Priests to slaves. What I am trying to say is, whatever vocation you are in, it is a holy vocation. God has called you to it and is using you in it.
Below is a brief commentary on the meaning of the Augsburg Confession Articles XIV and XV.
XV. 1: Some people misunderstand Luther’s intentions in the Reformation. Luther was not trying to begin a new church, nor even a separate denomination. In this Augsburg Confession, Melanchthon (Luther’s associate) and the other reformers were attempting to bring greater unity in the Church. As they considered some of the differences, they understood that some of the Church practices were adiaphora (meaning they were not commanded or condemned in Scripture) and were thus likely to vary. This was not troublesome to them, or a matter of salvation. In these things “all things are permissible, but not all are beneficial” to quote St. Paul. It is clear that sin should be avoided, including false doctrines. Slightly less clear, but still important is the matter of good order. St. Paul states that worship ought to be kept in good order (I Corinthians 14:26, 40), and order and peace should characterize our gatherings “For God is not a God of confusion but of peace (I Cor. 14:33a).” Rather than separating from the Catholic Church, the goal was to rid the Church of error, sin and things that were not beneficial while uniting on the clear teachings of Scripture in brotherly love and common faith. This was not a rebellion, but an attempt at reformation with hopes of unity in the truth.
XV.2: This is not because one is saved by keeping good order, but because it is beneficial to all to avoid chaos, sin, and unhelpful practices, and to be unified in things that bring “peace and good order.”
XV.3: Here it is stated all the more clearly that we cannot earn God’s favor or our salvation by our good works, clever church programs, and events, or by some church practice that supposedly works as some sort of magical rite (see Sacraments ≠ Magic). When it refers to “propitiating God” it speaks of an attempt to buy God’s favor or earn it by giving Him good works or something to satisfy Him. This is impossible for us to do, but was already done by Jesus as He lived the perfectly obedient and sinless life (active righteousness) and paid our debt to God in His death on the cross (passive righteousness).
 Theodore G. Tappert, ed., The Book of Concord the Confessions of the Evangelical Lutheran Church. (Philadelphia: Mühlenberg Press, 1959), 36–37.