Evidence for God from Science

John 20: 21Again Jesus said, "Peace be with you! As the Father has sent me, I am sending you." 22And with that he breathed on them and said, "Receive the Holy Spirit.

The disciples received the Holy Spirit at Pentacost. (Acts 2)

Did they receive the Holy Spirit twice? Seems unlikely to me.

So what is the account in John 20:21-22 all about?

Thank you.

He said to receive the Spirit, not that they were given the Spirit at that time. To me it seems like He was, more or less, giving them the command to accept the Spirit.