Paul leaves Corinth to head back to Jerusalem and Antioch. Possibly his trip to Jerusalem is in response to his having taken a Nazarite vow, the conclusion of which required sacrifice in the Jerusalem Temple. Possibly Paul had taken this vow in order as part of him being a Jew to win Jews. Along the way he stops at Ephesus, the largest city in the Aegean Sea region. Paul stops only briefly but promises a return to Ephesus.
Was Apollos a Christian when he met Priscilla and Aquila? I think so. He was competent in the Scriptures, had been instructed in the way of the Lord and taught accurately and boldly the things concerning Jesus. It says that he only knew the baptism of John. Therefore, he needed Priscilla and Aquila to take him aside and explained to him the way of God more accurately. My guess is that if he only knew the baptism of John then he may have known about John pointing to Jesus as the messiah and even have known about Jesus’ words and deeds of power. Perhaps he was deficient in his knowledge of the death and resurrection of Jesus. The result of Priscilla and Aquila’s having explained to him the way of God more accurately is that when he goes to Corinth he was able to greatly help those who through grace had believed and he powerfully refute the Jews in public, showing by the Scriptures that the Christ was Jesus.
The next pericope describes disciples of John the Baptizer. Unlike Apollos, these know John but do not know Jesus evidenced by their not having received the Holy Spirit. Paul explains the way of God more fully to them by telling them that John baptized with the baptism of repentance, telling the people to believe in the one who was to come after him, that is, Jesus. This they do and are baptized in the name of Jesus. Paul’s laying of hands upon them, as Peter and John had with the Samaritans, results in the Holy Spirit coming upon them evidenced by speaking in tongues (as had occurred at Pentecost).
In Ephesus, Paul’s ministry takes on the same pattern as at Corinth. First in the synagogue, then withdrawing and speaking to the Gentiles (the hall of Tyrannus). After two years all the residents of Asia heard the word of the Lord, both Jews and Greeks. Note that Christianity is again called ‘the Way’ on 19:9. We also learn that the proclamation of the Word was accompanied by signs and wonders: And God was doing extraordinary miracles by the hands of Paul, so that even handkerchiefs or aprons that had touched his skin were carried away to the sick, and their diseases left them and the evil spirits came out of them.
The final story in the Aegean Sea mission relates to some Jewish exorcists. These exorcists, like Elymas at Cyprus, oppose Paul. Not by rejecting Jesus as Elymas had done but rather by co-opting the name Jesus as one of the names in their sorcery toolbox. These seven sons of a Jewish priest were into syncretism – they would mix and match different religious practices for their own advancement and influence. When they attempt to exercise power over demons “by Jesus whom Paul proclaims”, they demons acknowledge both Jesus and Paul but then leaped on them, mastered all of them and overpowered them, so that they fled out of that house naked and wounded.
Luke goes on to say: And this became known to all the residents of Ephesus, both Jews and Greeks. And fear fell upon them all, and the name of the Lord Jesus was extolled. Also, many of those who were now believers came, confessing and divulging their practices. And a number of those who had practiced magic arts brought their books together and burned them in the sight of all. And they counted the value of them and found it came to fifty thousand pieces of silver. In other words, Jesus is powerful, and syncretism is out!
With the threat to the church removed, Luke concludes the Aegean Sea mission with the same words he has used to conclude previous sections: So the word of the Lord continued to increase and prevail mightily.