“I will pour out my spirit on every sort of flesh,” says Jehovah, “and your sons and your daughters will prophesy . . . And even on my male slaves and female slaves I will pour out my spirit.” (Joel 2:28, 29) That outpouring of God’s spirit did not occur as soon as the Israelites were brought back from Babylon to their homeland. Rather, it took place centuries later, at Pentecost 33 C.E. How do we know?

15. According to Acts 2:16, 17, what adjustment to the text of Joel 2:28 did Peter make, and what does that indicate?

¹⁵ Under inspiration, the apostle Peter applied Joel 2:28, 29 to an amazing event that took place on that day of Pentecost. About nine o’clock that morning, there was a miraculous outpouring of holy spirit that moved those who received it to begin speaking “about the magnificent things of God.” (Acts 2:11) Under inspiration, Peter used slightly different wording when quoting Joel’s prophecy. Did you notice what adjustment he made? (Read Acts 2:16, 17.) Instead of beginning the quotation with the words “after that,” Peter said: “And in the last days”​—in this context, the last days of the Jewish system of things—​God’s spirit would be poured out “on every sort of flesh.” This indicates that considerable time had passed before Joel’s prophecy was fulfilled.

16. What effect did God’s spirit have on the preaching work in the first century, and what about today?

¹⁶ It was after that remarkable outpouring of God’s spirit in the first century that the preaching work began to go forward to the greatest extent. By the time the apostle Paul wrote his letter to the Colossians, about 61 C.E., he could describe the good news as being preached “in all creation under heaven.” (Col. 1:23) In Paul’s day, “all creation” meant the world as it was then known. With the help of Jehovah’s powerful holy spirit, the preaching work has expanded much more in our day​—“to the ends of the earth”!​—Acts 13:47; see the box “I Will Pour Out My Spirit.”