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: https://christianity.stackexchange.com/q/26180/11471 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.