Acts is great literature. Great literature has many layers of subtle meaning and Acts is no exception. Acts 13 sees the beginning of the first missionary journey. Note how Luke uses the names of people and places to provide emphasis, irony, comparison, and contrast.

Barnabas and Saul are sent on their way (v. 2). Note that Barnabas is listed before Saul in this verse. This becomes significant as we read of their progress in subsequent chapters.

Their first stop is Cyprus, Barnabas's hometown (see Acts 4:36). As they travel, they move from east to west and, even though the Gentile church has commissioned them, they begin by preaching in the synagogue at each town (v. 5).

In Paphos, they meet a Jewish sorcerer, Bar-Jesus (v. 6), a name that literally means ″son of Jesus″. This man acts as an advisor to the Roman representative, Sergius Paulus. In verse 8, Luke uses the sorcerer's nickname, Elymas, subtly highlighting his heretical character. This man is a Jew dabbling in magic, something explicitly forbidden by God's law (see Deuteronomy 18:10-11).

Saul recognises the sorcerer's true character. He is not a ″son of Jesus″, but a ″child of the devil″ (v. 10). The man is struck with blindness. This is the first sign, or miracle, God performs through Saul and it is a declaration of judgment, very much like Saul's own experience (see Acts 9:8-9).

Sergius is an intelligent man and, upon seeing what happened to his advisor and, having heard the word of God, he believes (v. 12).

From this point on in Acts, Luke uses Saul's Roman name, Paul, and this is another example of his subtle use of names to convey meaning. In the wider context of Acts, Paul is a more fitting name for the apostle, given that his ministry extended across the Roman world.

In Acts 13, Luke uses the name change to indicate a close connection between the Senate's representative, Sergius Paulus, and God's representative, Paul. Perhaps his intention is to show that Paul is on equal footing with these Roman provincial leaders.