What does Acts 13:10 mean?

Paul is presenting the saving story of Jesus to a Roman proconsul on the island of Cyprus (Acts 13:2–4). The proconsul is under the influence of a Jewish false prophet (Acts 13:6–8) who is trying to discredit Paul. Filled with the Holy Spirit, Paul declares the false prophet to be a "son of the devil." The term "son of" in the Bible does not necessarily mean a literal biological child; it can mean one who emulates another's character. In this case, Paul's accusation is particularly ironic since the magician's name is Bar-Jesus which literally means "son of Jesus."

Gentiles in the Roman Empire had their pick of dozens of gods and goddesses to worship, and all were called to worship the emperor as a god. But people often grew weary of uninspired rituals and stories; they wished for something more powerful and mysterious. Romans often sought excitement in the esoteric religions of the east, including Judaism. Grifters, such as Bar-Jesus, took advantage of this honest search for God and promised truth in exchange for money, in absolute contrast to the approach Paul develops (1 Corinthians 9:3–12).

"Deceit" is from the Greek root word dolos. It means "craft or guile." "Villainy" is from the Greek root word rhadiourgia. It means "cunning and mischief." Bar-Jesus could have invited Sergius Paulus to the local synagogue where the proconsul could have become a "God-fearing" Gentile according to Judaism. Instead, he used the leader for his own gain.