One of the main criticisms the Reformers leveled at the Roman Catholic Church was its dualistic scheme of spirituality. The truly spiritual ones were the priests and others in church leadership, the monks and nuns sequestered from ordinary life, and, after death, the saints, who were super-exalted Christians. The Reformers didn’t consider this caste system to be biblical. It introduced artificial distinctions into the Christian church. It created a dualistic spirituality. The priesthood was called to be entirely committed to God, but the laity could live a life of mediocre commitment as long as they came to Saturday confession and Sunday mass. The Reformers knew that Rome got this point all wrong. Every Christian should be a committed Christian, and the only difference between church leadership and the laity is over giftedness, not over a qualitative level of spirituality. 
This meant that vocation itself could be, and should be, holy. The office of priest or the calling of a monk or nun was not a higher or more spiritual calling than a jewelry peddler or shoe cobbler. We might call this the Protestant sanctification of vocation, and it had a profound effect on culture. It meant that the shoe cobbler or wool merchant could look on his (or her) work as distinctively Christian. It wasn’t simply that the culture itself is Christian; every person’s calling within that culture should be Christian. It was, in effect, the Christianization — the Gospelization — of all of life.
This sanctification of vocation is essential to a truly consistent Christian Gospel. Unfortunately, evangelical Protstants have developed their own version of spiritual dualism. In these quarters, they have tended to exalt the work of the pastorate and missionaries and Christian day school teachers as somehow “the Lord’s work,” while everything else is acceptable, but secondary. If you really wish to serve the Lord without qualification, you must “surrender your life” to the ministry. Oddly, no one ever speaks of “surrendering his life” to writing computer code or selling or repairing automobiles or piloting commercial aircraft or making millions of dollars investing prudently in the stock market. But in biblical terms, if in whether we eat or drink and in whatever we do we, we do all to God’s glory (1 Cor. 10:31), if God has called us to one of these vocations or another outside “full-time ministry,” we surrender our life to that vocation. To the extent that we faithfully serve God in that vocation in terms of God’s word, this is our highest possible calling.
We might talk of “full-time” Gospel ministry, but we need to realize that the Christian physician and ticket agent and software engineer and barista and auto mechanic, to the extent that they are faithful to the globally redemptive message, are just as much Gospel ministers as the pastor and Sunday school teacher and missionary.
 Alister McGrath, Christianity’s Dangerous Idea (New York: HarperCollins, 2007), 335–338.