The Gospel Is Preached

Acts 8:5-6 – Then Philip went down to the city of Samaria, and preached Christ unto them. And the people with one accord gave heed unto those things which Philip spake, hearing and seeing the miracles which he did.

The Gospel Is Obeyed

Acts 8:12 – But when they believed Philip preaching the things concerning the kingdom of God, and the name of Jesus Christ, they were baptized, both men and women.

Samaritans Were Born Again

Acts 8:14-17 – Now when the apostles which were at Jerusalem heard that Samaria had received the word of God, they sent unto them Peter and John. Who, when they were come down, prayed for them, that they might receive the Holy Ghost (For as yet he was fallen upon none of them: only they were baptized in the name of the Lord Jesus).  Then laid they their hands on them, and they received the Holy Ghost.

The people of Samaria did not automatically receive the Holy Ghost when they believed and were baptized.  How did Phillip know, that the people of Samaria were missing the baptism of the Spirit, prior to Peter and John coming?