SCRIPTURE, not an opinion, testifies to the fact that the salvation message and instructions were provided to the Samaritans and Gentiles after having initially been given to the Jews.
Luke notes Peter's words to the crowd at Pentecost. He explains how after complying with the instructions, the new disciples travel out of Jerusalem and begin witnessing the truth to others throughout the World.
Luke's letter records specific episodes where obedience to Peter's initial instructions to the Jews were required of Gentiles, Samaritans, and Ephesus disciples, and others as well. (Acts 8:12-18, 10:44-48, 19:1-6, 22:16 Paul, 8:35-40 Eunuch, 16:28-33 Jailer/family, 16:14-15 Lydia/family, 18:8 Crispus/Corinthian believers)
Where does one find in the Word that the infilling of the Holy Ghost is all that is required for one to be reborn/saved?