The first instance in Acts which Paul may or may not refer to Satan occurs in his first missionary journey. He and Barnabas preach before the proconsul of Paphos, and a Jewish Magician (Magos) named Elymas bar-Jesus opposed them. Then Paul, “filled with the Holy Spirit,” denounces him roundly, calling him “son of an enemy” (huios diabolou) or “son of Devil” (huios Diabolou) and “enemy of all goodness.” The Lord will punish him now by making him blind “for a time,” he says, and immediately there falls on him “a mist and a darkness” (skotos) (Acts 13.6-11).
Elymas’s real father was named “Jesus,” to judge from his name. Who is Paul now saying his father is? Remember that we speculated above (chap. 3.4)that, since Paul always refers to Satan and never to Devil, he could have interpreted the envious diabolos who brought in Death in the Book of Wisdom as an enemy other than Satan, say, Sin. Could he have some such personified or abstract adversary in mind here for Elymas?
We noted in the same place above that even though diabolos is lacking a definite article in the genitive, it could still refer to “Devil,” the proper name. In other words, huios diabolou could mean huios tou Diabolou, “son of Devil.” So, it’s possible that Paul (or Luke reporting Paul) is referring to Devil here. But if that is what he meant, Paul would more likely have said, huios Satana or huios tou Satana, “son of Satan,” or even angelos Satana, as he refers to the “thorn in my flesh” (2.Cor. 12.7).