How were people baptized in the name of Jesus without the Holy Spirit in Acts 8? My question regards this passage:


  Acts 8:14-17 ESV Now when the apostles at Jerusalem heard that Samaria had received the word of God, they sent to them Peter and John, who came down and prayed for them that they might receive the Holy Spirit, for he had not yet fallen on any of them, but they had only been baptized in the name of the Lord Jesus. Then they laid their hands on them and they received the Holy Spirit.


My understanding of the indwelling of the Holy Spirit is that it comes with believing in Jesus immediately like it says in Ephesians 1:


  Ephesians 1:13 ESV  In him you also, when you heard the word of truth, the gospel of your salvation, and believed in him, were sealed with the promised Holy Spirit,


What's up with this case in Samaria?



NOTE: I've looked at this question: Why was it necessary for some people to receive the Gift of the Holy Ghost by the laying on of hands and others just received it after believing? and feel that it asks specifically about hand-laying, which I am not, so its answers don't quite answer mine. I'm just wondering why the believers didn't get the Holy Spirit even though they had become believers.
You are correct that all believers have the Holy Spirit indwelling them from conversion on. However, Samaria is an instance of Spirit Baptism.

Luke consistently presents a pattern of the Baptism in the Holy Spirit being distinct from and subsequent to salvation1. These texts in Acts 1, 2, 8, 9, 11, and 19 form the basis of the Classical Pentecostal "Doctrine of Subsequence." (Subsequence is one of the core distinctives of the Assemblies of God. They address it in the Statement of Fundamental Truths #7.)

That receiving the Spirit is distinct from salvation can be seen numerous times in Acts. 


In Acts 1:4,5, Jesus himself, while speaking to those who had trusted in Him as Messiah and Lord, said "Do not leave Jerusalem, but wait there for what my Father promised, which you heard about from me. For John baptized with water, but you will be baptized with the Holy Spirit not many days from now." The Baptism in the Spirit was yet to come for these believers. Drawing the distinction even more clearly between receiving the Spirit and being baptized in the Spirit, prior to this (John 20:22), Jesus breathed on them and said, "Receive the Holy Spirit." Now, He is saying that their Baptism in the Spirit is yet to come.
Before the first outpouring (Acts 2), the 120 are specified as "disciples/believers" (Acts 1:15) and "brethren" (1:16), that is, they were already baptized believers but the Holy Spirit had not come upon them (Acts 1:5, 8) but were now receiving the Spirit. 
As you mention in Acts 8, belief and Spirit Baptism are presented as distinct. 
In Acts 9:17, the believer Ananias calls Paul "brother" before Paul receives the Spirit. 
In Acts 19, the recipients follow Paul's command for water Baptism in Jesus' name (19:5). It is only after this, (vs 6) that the Holy Spirit came upon them.


An example against this might be Cornelius' house. There receiving the Spirit (Acts 10:44-46) comes before water Baptism and at the same event as conversion.2 Since no amount of time is mentioned, it cannot definitively be stated as subsequent. However, the pattern in the rest of Acts shows a period of time to be normal.

The Holy Spirit indwells all believers at conversion, but the baptism in the Holy Spirit is shown in Acts to be distinct and subsequent almost all of the time.



1 "...a temporal separation is typical of the outpourings of the Spirit in Acts," Roger Stronstad, The Charismatic Theology of St. Luke, Baker Academic, reprinted 1990, pg. 65.

2French L. Arrington, (The Acts of the Apostles: an Introduction and Commentary. Peabody: Hendrickson, 1988, pg. 113) states that these men were already saved before Peter arrived. He argues this based on 1) how Peter leaves out any mention of conversion or repentance in his sermon and 2) that the phrase "you know" is also used by Paul to emphasize doctrine that the recipient already accepts. However, as helpful as this interpretation is to the Doctrine of Subsequence, Peter does give them a call to repentance when he says "everyone who believes in him receives forgiveness of sins through his name" (vs. 43). Also, in 11:14, Peter says God sent him to take Cornelius a message "through which you and all your household will be saved." Thus, the household was not saved before the sermon.