Acts 8:4 Therefore, those who had been scattered went about preaching the word. 5 Philip went down to the city of Samaria and began proclaiming Christ to them. 6 The crowds with one accord were giving attention to what was said by Philip, as they heard and saw the signs which he was performing. ... 12 But when they believed Philip preaching the good news about the kingdom of God and the name of Jesus Christ, they were being baptized, men and women alike. ... 14 Now when the apostles in Jerusalem heard that Samaria had received the word of God, they sent them Peter and John, 15 who came down and prayed for them that they might receive the Holy Spirit. 16 For He had not yet fallen upon any of them; they had simply been baptized in the name of the Lord Jesus. 17 Then they began laying their hands on them, and they were receiving the Holy Spirit.
Acts 19:1 It happened that while Apollos was at Corinth, Paul passed through the upper country and came to Ephesus, and found some disciples. 2 He said to them, "Did you receive the Holy Spirit when you believed?" And they said to him, "No, we have not even heard whether there is a Holy Spirit." 3 And he said, "Into what then were you baptized?" And they said, "Into John's baptism." 4 Paul said, "John baptized with the baptism of repentance, telling the people to believe in Him who was coming after him, that is, in Jesus." 5 When they heard this, they were baptized in the name of the Lord Jesus. 6 And when Paul had laid his hands upon them, the Holy Spirit came on them, and they began speaking with tongues and prophesying.
These passages, plus the account, quoted above, in Acts 10, topple some neat, tidy, God-in-a-box schemes. In these several passages, becoming a believer, being baptized in water and receiving the gift of the Holy Spirit (being baptized in the Holy Spirit) are shown to be individual, separable, events/experiences, happening in no particular order other than becoming a believer being first. In Acts 10, Cornelius and family received the Holy Spirit first and then were baptized in water; in Acts 8 and 19, the believers in Samaria and Ephesus were baptized in water first and afterwards received the gift of the Holy Spirit. In Samaria, while the passage does not state exactly how long, the distance from Jerusalem to Samaria dictate that a day or more separated the Samaritans becoming believers and being baptized from their receiving the gift of the Holy Spirit. I'll leave the spiritual “physiology” and “physics” of it to God, but these passages make clear that the indwelling of the Holy Spirit that every believer has is something different from having the gift of the Holy Spirit. Speaking of neat and tidy God boxes, Part 1 … some Pentecostals teach that if some one does not speak in tongues they are not saved. The Acts 8 and Acts 19 accounts contradict this teaching; the Samaritans and Ephesians are clearly identified as being believers prior to their receiving the gift of the Holy Spirit (and speaking in tongues). Speaking of neat and tidy God boxes, Part 2 … traditional Pentecostals teach that speaking in tongues is the evidence one has received the gift of the Holy Spirit. I believe these passages demonstrate that this teaching goes farther than Scripture does. Acts 8 makes clear that it was apparent to others when the Samaritan believers received the gift of the Holy Spirit, but does not mention what made it apparent. As for the believers in Ephesus, one very reasonable understanding of Acts 19 is that some were speaking in tongues, while others were prophesying – in other words, two “evidences”. While the incident in Ephesus was of sufficient import for Luke to recount (consider, how many hundreds or thousands of times might Paul have seen people become believers, be baptized in water, and/or receive the gift of the Holy Spirit? Incidents not recounted in the book of Acts?), I do not see the event of the Ephesian believers receiving the gift of the Holy Spirit being perceived by Paul and those accompanying him as unusual. To the contrary, the flow of Paul's actions show that he was simply bringing these believers into a more complete Christian faith and experience, of which receiving the gift of the Holy Spirit was a normal part.