A careful reading of the Acts of the Apostles, chapter 14, presents St Paul visiting the Anatolian cities of Iconium and of Lystra, then the major city of Antioch. Here, with Barnabas, Paul always first visited the Jewish synagogue, and addressed the Jewish elders and congregation, and later even made his message heard by Gentiles, that is non-Jews.
His words, and their positive or negative reaction in turn is recounted by the traditionally presumed writer of Acts, the physician Luke. The first converts to Christianity were usually Jews, then Gentiles. There was often resistance from both quarters, yet with some Paul drove the message home, even sometimes through wonders or miracles.
After Paul's shipwreck in Malta around 60 AD, there is no such account. Luke does not mention any preaching by Paul, he does not quote any of Paul's words, just deeds by Paul and by the native Maltese, whom he terms "barbarians", that is non-Greek-speakers. The Maltese islanders were religious and rather superstitious, yet merciful, grateful for his healing, and generous at his departure in loading the Alexandrian ship with all they needed.
Malta appears to have been a convenient harbour for Roman and Egyptian wheat ships plying the Mediterranean between Italy and North Africa: Naples or Ostia to Leptis Magna, Sabratha, Cyrene and Alexandria.
Malta does not appear to have possessed a Jewish synagogue, or a sizeable Jewish community then, though there were some traditionally in "Africa" (modern Tunisia), and on its island Jerba.
Who lived then on Malta and Gozo? The Hellenised Roman administrators, judging by the contemporary Maltese coinage inscribed in Greek, a garrison of Latin and possibly Greek speaking Roman officers and soldiers, and the native Neo-Punic speaking Maltese who may or may not have been able to communicate directly or indirectly with Paul, Luke and Aristarchus. Following this shipwreck, one is talking of 276 survivors, and the second Alexandrian ship's crew who had wintered at Malta on their way to Pozzuoli near Naples.
Luke makes no mention of preaching by Paul or by his two companions, or of Roman or Maltese converts. Some can possibly be surmised by experts, but our traditional approach to Paul's shipwreck and its aftermath may have played a lot on our traditional preachers' imagination, and legends may have gone down in our history as facts. This point bears correction, yet there is no clear proof in either direction, except possibly for scholars who have studied Jewish, Egyptian, Greco-Roman and Punic practices.