The above mentioned people who had been instructed to tarry at Jerusalem until they were baptized with the Holy Ghost were Christ's disciples and devoted followers including Mary, the mother of Jesus.
Acts 8:12-16 records these important facts "But when they believed Philip preaching concerning the kingdom of God, and the name of Jesus Christ, they were baptized both men and women. (v.13) Then Simon himself believed also: and when he was baptized, he continued with Philip and wondered, beholding the miracle and signs which were done. (v.14) Now when the apostles which were at Jerusalem heard that Samaria had received the word of God, they sent unto them peter and John: (v.15) who, when they were come down, prayed form them, that they might receive the Holy Ghost: (v.16) (for as yet he was fallen upon none of them: only they were baptized in the name of the Lord Jesus.) The above verses show clearly that the Samaritan converts were believers and were baptized in the name of Jesus but had not received the Holy Ghost until the apostles at Jerusalem came down and laid their hands upon them. Also in Acts 19:2, Paul asked the disciples of John "… Have ye received the Holy Ghost since ye believed?" Thus showing that you could be a believer and not have the Holy Ghost.
