Receiving the Holy Spirit after conversion Acts 8:14–17

How would [Southern] Baptist (SBC) churches explain Acts 8:14–17 in the giving of the Holy Spirit after initial conversion or belief? It had always been my understanding that the argument was the Holy Spirit was given to each believer at the moment of faith. Are we indwelt by the Spirit when we believe and if so why were the apostles needing to pray for them to receive Him? >Acts 8:14–17
14 Now when the apostles at Jerusalem heard that Samaria had received the word of God, they sent to 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 on any of them, but they had only been baptized in the name of the Lord Jesus. 17 Then they laid their hands on them and they received the Holy Spirit. ESV, © 2001