One of the key doctrines taught by Luther in the sixteenth century was the priesthood of all believers. That is an often misunderstood concept because it sounds as if Luther was saying that, with the advent of Protestantism, the idea of an ordained clergy is no longer necessary.
Luther did not do away with an ordained clergy. He understood that there was a particular function established in the New Testament for what we would call full-time Christian ministry or pastoral ministry.
What he was saying by the priesthood of all believers is that every believer is called to participate in the establishing and building of the kingdom of God. And every believer, whatever work he’s engaged in—banker, lawyer, Indian chief, baker, or whatever it may be—his work should be done to the glory of God. He should be subjecting his talents and gifts to live _coram Deo_, before the face of God, under the authority of God, and to the glory of God. This means that we should be wrestling with the biblical principles that teach us how to use our gifts and talents in a way that is serviceable to God and to humanity.
In the medieval church, vocation was restricted to the clergy for the most part. But in the Reformation it was said, “No, the farmer has a vocation, the banker has a vocation,” and so on. God calls all of us to do different aspects of different parts in developing His kingdom.