19:1 Having passed through - Galatia and Phrygia, which were termed the upper parts of Asia Minor. Certain disciples - Who had been formerly baptized by John the Baptist, and since imperfectly instructed in Christianity.

Acts 19:1 Parallel Commentaries

Whether Baptism May be Reiterated?
Objection 1: It seems that Baptism may be reiterated. For Baptism was instituted, seemingly, in order to wash away sins. But sins are reiterated. Therefore much more should Baptism be reiterated: because Christ's mercy surpasses man's guilt. Objection 2: Further, John the Baptist received special commendation from Christ, Who said of him (Mat. 11:11): "There hath not risen among them that are born of women, a greater than John the Baptist." But those whom John had baptized were baptized again, according …
Saint Thomas Aquinas—Summa Theologica

Ephesus
While Apollos was preaching at Corinth, Paul fulfilled his promise to return to Ephesus. He had made a brief visit to Jerusalem and had spent some time at Antioch, the scene of his early labors. Thence he traveled through Asia Minor, "over all the country of Galatia and Phrygia" (Acts 18:23), visiting the churches which he himself had established, and strengthening the faith of the believers. In the time of the apostles the western portion of Asia Minor was known as the Roman province of Asia. Ephesus, …
Ellen Gould White—The Acts of the Apostles

Days of Toil and Trial
For over three years Ephesus was the center of Paul's work. A flourishing church was raised up here, and from this city the gospel spread throughout the province of Asia, among both Jews and Gentiles. The apostle had now for some time had been contemplating another missionary journey. He "purposed in the spirit, when he had passed through Macedonia and Achaia, to go to Jerusalem, saying, After I have been there, I must also see Rome." In harmony with this plan "he sent into Macedonia two of them …
Ellen Gould White—The Acts of the Apostles