The Gospel and Limits to Vocation and Engagement (Acts 19:17-20)
Acts 19:13-16 presents an odd story that leads to the repentance of “a number who had practiced magic” (Acts 19:19). They collected their magic books and burned them publicly, and Luke tells us that the value of the scrolls burned by these converts was 50,000 drachmas. This has been estimated as the equivalent to 137 years of continuous wages for a day laborer or enough bread to feed 100 families for 500 days. Incorporation into the community of God’s kingdom has massive economic and vocational impact.
While we cannot be certain whether those who repented of their engagement in magic were repenting of a means of earning a living, such a costly collection of books was unlikely to have been a mere hobby. Here we see that the change in life precipitated by faith in Jesus is immediately reflected in a vocational decision—a result familiar from Luke’s Gospel. In this case, the believers found it necessary to abandon their former occupation entirely.
In many other cases, it is possible to remain in a vocation but necessary to practice it in a different way. For example, imagine that a salesperson has built a business selling unnecessary insurance to senior citizens. He or she would have to cease that practice, but could continue in the profession of selling insurance sales by switching to a product line that is beneficial for those who buy it. The commissions might be less (or not), but the profession has plenty of room for legitimate success and lots of ethical participants.
A much more difficult situation occurs in professions that could be done legitimately, but in which illicit practices are so thoroughly entrenched that it is difficult to compete without violating biblical principles. Many civil servants in high-corruption nations face this dilemma. It might be possible to be an honest building inspector, but very difficult to do if your official pay is $10 a week and your supervisor demands a $100 a month fee to let you keep your job. A Christian in that situation faces a difficult choice. If all the honest people leave the profession, so much the worse for the public. But if it is difficult or impossible to make a living honestly in the profession, how can a Christian remain there? This is something Luke discusses in Luke 3:9, when John the Baptist counsels soldiers and tax collectors to remain in their jobs but to cease the extortion and fraud practiced by most of their profession. (See "Luke 3:1-14" in Luke and Work at www.theologyofwork.org for more on this passage.)
Darrell Bock, Baker Exegetical Commentary on the New Testament: Acts (Grand Rapids: Baker, 2007), 605.