Most of the believers, other than the Apostles, leave Jerusalem from fear of Saul and other authorities, nut this just spreads the gospel to travelling Ethiopian eunuchs and to people in cities, including Samaria, Damascus (where Saul is converted), and Lydda and Joppa (where Dorkas is raised from the dead): Acts 8–9
It would have to be one of the more spectacular conversions: in a moment, Saul believed the same Christ he had so violently opposed.
But it wasn’t that Saul didn’t worship God. When a voice from heaven asked him Why are you persecuting me?, his response (a question) showed that he knew God’s voice:
Acts 9:5 Who are you, lord?
And God’s reply showed that God knew Saul needed a little, but not much, explanation:
Acts 9:5-6 I am Jesus, the one you are persecuting! Now get up and go into the city, and you will be told what you must do.
Within days, Saul was preaching Jesus in the Damascus Synagogue, and he was so effective that the only recourse the leaders had there was to try to kill him.