A COMMON procedure that could lead to a change in a person's status was the practice of adoption, something that could happen at any age and which generally marked the start of a new life for the one adopted. This practice is one of the complexities we face in understanding the imperial succession in Rome, which could involve emperors adopting either their own stepchildren or even complete outsiders.

Adoption represented a far more thoroughgoing reorientation of lifestyle and future prospects than would be the case today. To be adopted meant the cancellation of all one's debts, and a total reversal of an individual's previous fortunes; the adopted person not only took on the name of his or her new family but was entitled to all the privileges of that family, including full rights of inheritance.

In return, of course, the adoptee came under the control of the new family's head (invariably the father), who determined the future course of his or her life while offering safety, security, and family solidarity in exchange. In other words, an adopted person enjoyed exactly the same status as a person born into the family - something that Paul used as an appropriate metaphor for the gift of God's grace experienced through faith in Christ.

One further category worth noting is that of citizenship. In the earliest days, of course, citizenship was a localised concern: you were a citizen of whatever city or province you happened to be born into. More or less from the start, Roman citizenship had extended slightly beyond Rome itself, as provincial alliances with different areas of Italy were forged. But it was Augustus who extended the notion so that citizenship became a mark of distinction rather than a narrowly defined geographical designation. Paul is the most prominent New Testament example of a person who was a Roman citizen, and he exemplifies this non-geographical principle very well, for he could quite easily be regarded as a citizen of two cities: of Tarsus, his birthplace, and of Rome (even though, at that stage, it is unclear whether he had ever been to the city).

This is another theme that Paul used to illustrate his understanding of Christian faith, insisting that there was no intrinsic incompatibility between being a good citizen of Rome and owing loyalty to a "citizenship in heaven", which involved being "no longer strangers and aliens, but . . . citizens with the saints and also members of the household of God".

An individual could become a citizen by various routes: by being born to parents who were already citizens, as a reward for some special service on behalf of the empire (either commercial or military), or even as part of a package of privileges granted to freed slaves. Though in theory no distinction was drawn between these various pathways to citizenship, Paul used the fact that he was "born a citizen" to his advantage when dealing with Claudius Lysias, who had arrested him in Jerusalem but who had secured his own citizenship only on payment of "a large sum of money". It was usual for someone gaining citizenship under these circumstances to adopt his or her sponsor's name, which suggests that the tribune had only recently gained citizenship - in the time of Claudius, during whose reign it was evidently quite easy to purchase citizenship.

By New Testament times, citizenship involved very few formal duties other than loyalty to the empire, though it bestowed important privileges, including exemption from degrading punishments such as flogging and crucifixion, and the right to appeal to the courts in Rome over the head of the local judiciary - both of which feature in the stories of Paul.

Extract from The World of the Bible by John Drane, published by Lion Hudson plc 2014 (£9.99 (CT Bookshop £8.99); 978-0-7459-5645-9); reproduced with permission.