The gift of the Holy Spirit is simply a degree of God's Spirit by which He indwells believers who have made a covenant to obey Him. Saying that you "accept" Christ is not enough. Before you can receive this gift, you must have a faith that bears fruit, repentance that is more than a change of mind, and a willingness to obey.
Does the gift of the Holy Spirit precede or follow water baptism? The pattern that Christ established would indicate that it is entirely appropriate for water baptism to precede the baptism of the Holy Spirit.
Then cometh Jesus from Galilee to Jordan unto John, to be baptized of him. But John forbad him, saying, I have need to be baptized of thee, and comest thou to me? And Jesus answering said unto him, Suffer it to be so now: for thus it becometh us to fulfil all righteousness. Then he suffered him. And Jesus, when he was baptized, went up straightway out of the water: and lo, the heavens were opened unto him, and he saw the Spirit of God descending like a dove, and lighting upon him: and lo a voice from heaven, saying, This is my beloved Son, in whom I am well pleased.
Matthew 3: 13-17
When Peter preached the gospel on the day of Pentecost, Acts 2:36 tells us that the people were "pricked in their heart [s]." They believed the gospel but had not yet received that degree of God's Spirit called the "gift of the Holy Ghost." Why? Because faith "alone" is not enough. The believer must also repent of his or her sins (Acts 3:19). Remember that repentance is necessary for salvation.
Now when they heard this, they were pricked in their heart, and said unto Peter and to the rest of the apostles, Men and brethren, what shall we do? Then Peter said unto them, Repent, and be baptized every one of you in the name of Jesus Christ for the remission of sins, and ye shall receive the gift of the Holy Ghost.
In Acts 8, believers at Samaria had been baptized in water but had not yet received the gift of the Holy Ghost. As we mentioned earlier, being born of water could not occur unless faith, repentance and surrender were clearly evident. Despite this, they had still not received the gift of the Holy Ghost:
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..... 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.
Acts 8: 12-17
How could this be? This seems to contradict everything that evangelical ministers teach? Isn't the indwelling of the Holy Spirit always granted to people when they first believe? Why didn't this occur in Samaria? Because it is possible for the gift of the Holy Spirit to be granted sometime after initial belief.
Theologians argue about whether it was more "normative" in the New Testament church to receive this gift at the point of initial belief or by laying on hands. Because this is intended to be a short explanation, we merely want to establish that the gift of the Holy Ghost can occur at a different time from initial belief and that laying on hands is a legitimate means by which God conveys that gift (I Timothy 4:14; II Timothy 1:6). We should find this pattern wherever Christ's true church exists.