Priscilla and Aquila mentored Apollos in Ephesus and he went on to have a ministry that was influential to people in a wide geographical area. There were also believers there who hadn't heard about the baptism of the Holy Spirit. When Paul prayed with them and laid hands on them, they received the Holy Spirit and spoke in tongues. To them, this was a confirmation of the prophecy in Joel chapter 2. As people responded to Paul's preaching, Demetrius and others associated with the temple of Artemus confronted Paul because they saw this as a threat to their religion and their occupation of making idols. After continuing to preach in Ephesus and also write the book of Romans, Paul Paul traveled to a few more cities, then left for Jerusalem. He stopped in Ephesus to say goodby to the elders that he had relationship with, and charged them to watch over and encourage the believers there.