But you will receive power when the Holy Spirit comes on you. Then you will be my witnesses in Jerusalem, in all Judea and Samaria, and to the farthest point on earth.”
The prophets were shown that they weren’t serving themselves. Instead, they were serving you when they spoke about the things that you’ve now heard from those who preached the good news to you with the help of the Holy Spirit sent from heaven. Even angels long to look into these things.
When he said this, he was referring to the Holy Spirit. Those who believed in Jesus would later receive the Spirit. But at that time, the Spirit had not been given, because Jesus hadn’t been glorified yet.