"But Peter, standing up with the eleven, raised his voice and said to them, 'Men of Judea and all who dwell in Jerusalem, let this be known to you, and heed my words. For these are not drunk, as you suppose, since it is only the third hour of the day. But this is what was spoken by the prophet Joel: 'And it shall come to pass in the last days, says God, that I will pour out of My Spirit on all flesh, your sons and your daughters shall prophesy, your young men shall see visions, your old men shall dream dreams. And on My menservants and on My maidservants I will pour out My Spirit in those days; and they shall prophesy. I will show wonders in heaven above and signs in the earth beneath: blood and fire and vapor of smoke. The sun shall be turned into darkness, and the moon into blood, before the coming of the great and awesome day of the LORD. And it shall come to pass that whoever calls on the name of the LORD shall be saved'" (Acts 2:14-21).
The apostle Peter, showing his natural abilities as a leader as well as fulfilling his duty to open the doors to the kingdom of heaven (cf. Matt. 16:19), stood up "with the eleven" (not the 119), and responded that he and the other apostles were not drunk as had been charged by some in the crowd. He stated that they could not have been drunk since it was "only the third hour of the day." Such is not an infallible argument, but it would have been unusual for even the heaviest of drinkers to be intoxicated at this early hour (particularly on a feast day). Peter's powerful speech that follows is an infallible proof, however, that he was not inebriated. The language seems to imply that all twelve took part in the preaching. Perhaps Peter spoke first and others acted as interpreters for the people gathered around each of them. Or, perhaps every apostle preached his own sermon under inspiration of the Holy Spirit and only Peter's is recorded (and only a portion of it at that; cf. 2:40). It is worth observing that Peter stressed the need for his audience to "heed his words" (Acts 2:14). Before the end of his sermon, he explicitly instructed them as to what they must do (cf. Acts 2:38ff).
After answering the charge of drunkenness, Peter proceeded to the next logical step--explaining what the large crowd had both seen and heard (i.e., the sound as of a rushing mighty wind, the divided tongues as of fire, and the sudden fluent speaking in many foreign languages by the apostles). The Holy Spirit, not alcohol, was the source of these great signs and wonders. The prophet Joel, in Joel 2:28-32, had previously made a prediction concerning this very matter and, according to Peter, the activities of that Pentecost were the beginning of the fulfillment of his prophetic words. There are many details mentioned in the prophecy which were not fulfilled on Pentecost but would be fulfilled as "the last days" continued.
Before considering the prophecy in detail, it is helpful to be aware of the general outline Peter followed in his sermon. The same major points were made regularly by the apostles when they addressed Jewish audiences:
The Spirit of God would be poured out "in the last days" (Acts 2:17). The inescapable conclusion is that the events of Acts 2 occurred during "the last days." Elsewhere we learn that Christ's ministry also occurred during this final period of time (cf. Heb. 1:1,2) This final age (or the Messianic era, as it is called by some) will continue until the Lord returns. Mankind has been in the last days nearly 2000 years now, and no man knows when the last days will end (cf. Matt. 24:36-44; Isa. 2:1-4).