We need to read earlier in the chapter to understand the context of these verses.  Let’s read Acts 2:1-4, “And when the day of Pentecost was fully come, they were all with one accord in one place. And suddenly there came a sound from heaven as of a rushing mighty wind, and it filled all the house where they were sitting. And there appeared unto them cloven tongues like as of fire, and it sat upon each of them. And they were all filled with the Holy Ghost, and began to speak with other tongues, as the Spirit gave them utterance.”  This was the day of Pentecost, the birthday of the Church.  On this day, all the believers gathered together were filled with the Holy Spirit.  Since this day, all believers on the Lord Jesus Christ receive and are sealed with the Holy Spirit at the moment of their salvation.  (Ephesians 1:13-14; 4:30). 

There was a great number of believers from different countries and this phenomenon caused many to wonder about what was going on.  These people spoke in ‘other tongues’, but “every man heard them speak in his own language.” (Verse 6).  As people began to wonder, some accused these people of being drunk.  We then read in verses 14-15, “But Peter, standing up with the eleven, lifted up his voice, and said unto them, Ye men of Judaea, and all ye that dwell at Jerusalem, be this known unto you, and hearken to my words: For these are not drunken, as ye suppose, seeing it is but the third hour of the day.” 

Now let’s read Acts 2:16-21, “But this is that which was spoken by the prophet Joel; And it shall come to pass in the last days, saith God, I will pour out of my Spirit upon all flesh: and your sons and your daughters shall prophesy, and your young men shall see visions, and your old men shall dream dreams: And on my servants and on my handmaidens I will pour out in those days of my Spirit; and they shall prophesy: And I will shew wonders in heaven above, and signs in the earth beneath; blood, and fire, and vapour of smoke: The sun shall be turned into darkness, and the moon into blood, before that great and notable day of the Lord come: And it shall come to pass, that whosoever shall call on the name of the Lord shall be saved.”  Peter quoted from Joel 2:28-32.

Actually, the events of Pentecost were not a complete fulfillment of Joel’s prophecy. Most of the events described in verses 17-20 did not take place at this time. But what did happen at Pentecost was a PREVIEW of what would happen in the last days, prior to the great and tremendous day of the LORD.  The events of Pentecost could not have fulfilled Joel’s prophecy, for the Lord’s return is yet spoken of in   Acts 3:19 which says, “Repent ye therefore, and be converted, that your sins may be blotted out, when the times of refreshing shall come from the presence of the Lord.”  This is saying that if there was national repentance and Israel received the One they had crucified, He would come back and bring in the day of the Lord.  The quotation from Joel is an example of a Bible prophecy which has a partial fulfillment at one time and a complete fulfillment at a later time.

It is just prior to the glorious return of the Lord when there will be wonders in heaven and signs on the earth.  We read of that in Matthew 24:29-30, “Immediately after the tribulation of those days shall the sun be darkened, and the moon shall not give her light, and the stars shall fall from heaven, and the powers of the heavens shall be shaken: And then shall appear the sign of the Son of man in heaven: and then shall all the tribes of the earth mourn, and they shall see the Son of man coming in the clouds of heaven with power and great glory.”  This speaks of the signs and wonders that occur just before the Lord returns to set up His kingdom on the earth.  This is when the prophesy will be completely fulfilled.

So, here on this special day, the Lord was pleased to offer an example to the believers what would occur prior to the Lord’s return to the earth.  What a glorious day that will be.  Although we wait for the rapture of the church, this event is also a wonderful display of the Lord’s power and plan.  (CC)  (520.6)