Why do you need to receive the gift of the Spirit again?

Answer:

Several years ago I booked a trip to Bali to do some teaching there. To get there, I made stops in Japan and Singapore. It is proper to talk about the destination without having to list all the stops in between. When you do so, it doesn't mean those stops didn't happen.

Peter told the believing Jews in Acts 2:38, "Repent, and each of you be baptized in the name of Jesus Christ for the forgiveness of your sins; and you will receive the gift of the Holy Spirit." The destination was the receiving of the gift of the Holy Spirit (which is salvation). To get there from where they were, they needed to repent and be baptized.

In Ephesians 1:13-14, Paul is talking to Christians about how they had arrived at salvation. "In Him, you also, after listening to the message of truth, the gospel of your salvation -- having also believed, you were sealed in Him with the Holy Spirit of promise, who is given as a pledge of our inheritance, with a view to the redemption of God's own possession, to the praise of His glory" (Ephesians 1:13-14). Paul mentioned that Ephesians hear the message of truth and believed, which led them to receive the gift of the Holy Spirit.  However, nowhere does Paul state that these were the only things they had done. You assume that the sealing occurred immediately upon believing, but all Paul said was that the sealing came sometime after believing -- it could have been immediate or it could involve several more steps. This verse, by itself, is insufficient to draw a conclusion. But when combined with Acts 2:38, we know there were at least two more steps involved: repentance and baptism.

To get a proper picture, you have to examine all the passages dealing with salvation. See What Saves a Person for such a list.