The spiritual gifts were poured out in the "last days" just as the prophet Joel had told in Joel chap. 2.
"28 And it shall come to pass afterward, that I will pour out my spirit upon all flesh; and your sons and your daughters shall prophesy, your old men shall dream dreams, your young men shall see visions:
29 And also upon the servants and upon the handmaids in those days will I pour out my spirit." (Joel 2:28-29, KJV)
Peter stated on the day of Pentecost in the first century AD, about 30 -31 AD that what was happening, what the people saw and heard was what Joel had prophesied.
"15 For these are not drunken, as ye suppose, seeing it is but the third hour of the day. 16 But this is that which was spoken by the prophet Joel;" (Acts 2:15-16, KJV)
Peter said "this", what they saw and heard on the day of Pentecost was the fulfillment of Joel's prophesy that was to be poured out in "the last days". Therefore, the day of Pentecost occurred in the last days.
And in verse 17 Peter repeats Joel's prophesy.
The trouble many people have is recognizing when "the last days" were, and what they were the last days of. The current teaching that we are in the last days is very wrong. Peter told them they were living in the last days. He confirmed it again in his letter to the strangers living in Pontus, Galatia, Cappadocia, Asia, and Bythinia.
"19 But with the precious blood of Christ, as of a lamb without blemish and without spot: 20 Who verily was foreordained before the foundation of the world, but was manifest in these last times for you," (1 Pet. 1: 19-20, KJV)
When was Christ manifested on earth? Is He walking on earth now? Have we seen Him or heard Him teaching?
Those people who lived in the first century AD when Christ walked on this earth were the ones who saw Him, touched Him, spoke with Him, heard Him, and witnessed His sacrifice for our sins. Christ was manifested in the first century AD, and Peter said He was manifested "in these last times". Therefore, the last days spoken of in the record of the NT writings were those of the first century AD before the destruction of Jerusalem.
We must stop reading the words spoken almost 2,000 years ago as if they were just written to us yesterday. The NT is our past. It is history for us. The present tense and future tense words of the first century AD writings belong to that time period for those people who saw the manifestation of Christ on earth in the fullness of time (Gal. 4:4).
Once we can recognize that "this age" spoken of in the first century AD (Matt. 12:32; 13:22, 40) was the one in which they were living when Christ spoke those words to them almost 2,000 years ago, then we have to acknowledge that time matters. "This age" that belonged to their time period was "the last days" of the Mosaic covenant, and the second temple in Jerusalem. We cannot lift "this age" that existed during the first century AD out of time, and put it into our century.
It is not "this age" when we are reading it. It was "this age" when the apostles wrote it down; and when Christ said it. Lifting it out of the first century AD is anachronistic. "This age" = before the destruction of Jerusalem, and the last days of the Mosaic covenant. "The age to come" = the time after the destruction of Jerusalem, and the Christian age of the rule of the Messiah.
Christ had to fulfill all of the prophesies of the OT, including the second fulfillment of the destruction of Jerusalem which Joel - as well as Isaiah, Jeremiah, Ezekiel, Haggai, etc - had prophesied. Until that second temple was completely destroyed (Matt. ch. 24; Mark ch. 13; Luke ch. 16) in AD 70, the Mosaic covenant was still being practiced, and the animals were still being sacrificed in Jerusalem.
That was the termination point of the old covenant, and the double fulfillment of the prophesies of the destruction of Jerusalem. That was the "end of the age" and the "end of days" of Daniel's prophesy in Dan. 9:24 - 12:13.
During those days, those last days of the old Mosaic covenant, the newly baptized Jews on the day of Pentecost did not yet have the writings of the Apostles and disciples that we now call the New Testament. They had to know that what the Apostles were teaching was confirmed by and authorized by YHVH. The miracles presented through the gifts of the Spirit were to confirm that the words they spoke came from YHVH.
"`Men, Israelites! hear these words, Jesus the Nazarene, a man approved of God among you by mighty works, and wonders, and signs, that God did through him in the midst of you, according as also ye yourselves have known;" (Acts 2:22, YLT)
Peter told them that the miracles Christ had shown them were for confirmation that He was sent by, and approved by YHVH. The miracles the prophets performed throughout the record of the OT were always to confirm the existence of YHVH and that the prophets were truthfully speaking His words to the people.
It was the same in the first century AD. The people had the record of the OT through the Greek translation, what we call the Septuagint (or the LXX) which most attribute to Ptolemy II Philadelphus of Egypt. (1, 2) The people could check the Apostles' words of the prophets against the written record of the OT (Acts 17:11).
But, until about 54 - 56 AD they didn't have any written record of the NT scriptures. They needed confirmation from on High of the Apostles teaching of the gospel. The gifts of the Holy Spirit were the confirmation YHVH provided for their assurance so they could believe He had sent His Son to them. When that record was complete, "that which is perfect" (1 Cor. 13:10), then the spiritual gifts would die out as the people who held them died.
"For the promise is to you, and to your children, and to all that are afar off, even as many as the Lord our God shall call." (Acts 2:39, KJV)
The promise of the gifts of the Holy Spirit was
- "to you" - to those standing there on the day of Pentecost,
- "and to your children" - their children of that generation in the first century AD,
- "and to all that are afar off" - those gentile of the nations to whom Peter would open the door at the house of Cornelius (Acts ch. 10) and all other nations that would hear the gospel of Christ during the first century AD.
Those last days happened in the first century AD, and they were the "last days" of "this age" in which they lived 2,000 years ago at the end of the Mosaic covenant. When they spoke of "the age to come", they were speaking of the time in their future that would be in full force and effect after the destruction of that temple in Jerusalem. The age to come was their future, the Messianic age, the Christian age in which we now live.
"Unto him be glory in the church by Christ Jesus throughout all ages, world without end. Amen." (Eph. 3:21, KJV)
The people of the first century AD were still looking ahead to a prophetic time which had not yet been completed while they were teaching and learning the gospel of Christ. When we can recognize that reading an historical document requires that we read with the first audience perspective; that the words "soon", "at hand", and "shortly" meant exactly what they heard when they were spoken 2,000 years ago, then we can place the events in their proper time frame.
We are now living in what they called "the age to come", and we do not have to be afraid of any "end time" apocalypse. That apocalypse came upon their generation in the destruction of Jerusalem in AD 70. It already happened in their lifetimes, and those gifts of the Holy Spirit helped those early Christians to live through it.
There are many proofs from the scriptures of the time frame and many time texts that Christ and the disciples / apostles spoke to the people that confirm the first audience perspective. Most all of the posts at my blog detail them. See "Perspective" at the top menu, and you might begin with all of the series of "It's Not The End of The World" at ShreddingTheVeil
The Christian age has no end.
(All bold emphasis is mine.)
1) A Brief History of the Septuagint: here
2) Septuagint here