spread the name

But Peter, standing with the eleven, lifted up his voice and addressed them: “Men of Judea and all who dwell in Jerusalem, let this be known to you, and give ear to my words. 15 For these people are not drunk, as you suppose, since it is only the third hour of the day. 16 But this is what was uttered through the prophet Joel:

17 “‘And in the last days it shall be, God declares,

that I will pour out my Spirit on all flesh,

and your sons and your daughters shall prophesy,

and your young men shall see visions,

and your old men shall dream dreams;

18 even on my male servants and female servants

in those days I will pour out my Spirit, and they shall prophesy.

19 And I will show wonders in the heavens above

and signs on the earth below,

blood, and fire, and vapor of smoke;

20 the sun shall be turned to darkness

and the moon to blood,

before the day of the Lord comes, the great and magnificent day.

21 And it shall come to pass that everyone who calls upon the name of the Lord shall be saved.’ (Acts 2:14-21, ESV)

Peter quotes from Joel 2 about the "last days". they (and we) are no longer waiting for those "last days" when God is going to come down, because he did in Jesus. Now the Spirit is freely available to all Christians, not just specific people for a limited time as in the OT. The purpose of these effects of the spirit that are mentioned are not the things themselves. The purpose is not that the sons and daughters are delighted that they can now prophecy or that the young men are obsessed with visions while the old men live in a dream world. the purpose is that people will hear the name of the Lord so that they can call on it and be saved.