Acts 18:18-28 (ESV)
Paul Returns to Antioch
18 After this, Paul stayed many days longer and then took leave of the brothers  and set sail for Syria, and with him Priscilla and Aquila. At Cenchreae he had cut his hair, for he was under a vow. 19 And they came to Ephesus, and he left them there, but he himself went into the synagogue and reasoned with the Jews. 20 When they asked him to stay for a longer period, he declined. 21 But on taking leave of them he said, “I will return to you if God wills,” and he set sail from Ephesus.
22 When he had landed at Caesarea, he went up and greeted the church, and then went down to Antioch. 23 After spending some time there, he departed and went from one place to the next through the region of Galatia and Phrygia, strengthening all the disciples.
Apollos Speaks Boldly in Ephesus
24 Now a Jew named Apollos, a native of Alexandria, came to Ephesus. He was an eloquent man, competent in the Scriptures. 25 He had been instructed in the way of the Lord. And being fervent in spirit,  he spoke and taught accurately the things concerning Jesus, though he knew only the baptism of John. 26 He began to speak boldly in the synagogue, but when Priscilla and Aquila heard him, they took him and explained to him the way of God more accurately. 27 And when he wished to cross to Achaia, the brothers encouraged him and wrote to the disciples to welcome him. When he arrived, he greatly helped those who through grace had believed, 28 for he powerfully refuted the Jews in public, showing by the Scriptures that the Christ was Jesus.