Another identifiable group that came to John were the tax collectors, many of them. These three groups had responded to John’s preaching and were wanting to put into practice his exhortation to repent and to show their repentance in a practical way.
There are some jobs which a believer cannot do. He cannot do anything that, as part of the job, involves him in sin, in breaking God’s commandments, or in encouraging others to break God’s commandments. In some cases this is a necessary part of the job, while in other cases it can be avoided while still carrying out the work. In the first case it is part of our separation from the world to have nothing to do with those activities. There may be pressure on us to do our work dishonestly, or in such a way that others are harmed, but that is not an essential part of the work. That could be either because we see some gain for ourselves, some extra earthly reward, or because we have pressure put on us to work in that way. This was the case with the tax collectors among the Jews. The tax collectors were wealthy enough to purchase the right to collect taxes from the Romans, but having acquired this right, they found themselves with an opportunity to make a considerable profit for themselves by extorting their fellow countrymen.