Acts 2:17And 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:
Joel 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:”
With the passing of time, the apostles, in accordance with the will of God and the needs of the Church, ordained, first, deacons and afterwards presbyters (priests), and finally bishops, to whom they gradually transmitted a portion of their responsibilities. The deacons were ordained to receive and distribute the offerings given to the Church, and at the same time they served the bishops and priests during the performance of the divine services and mysteries; the presbyters (priests) taught and performed their sacred functions in dependence on the bishops; and the bishops excercised oversight over the order of the Church, kept watch over the activities and the very life of the sacred ministers and all members of the Church, and in general possessed a right to teach, perform sacred actions and govern the Church second only to that of the apostles. After the repose of the apostles fullness of authority in the Church passed to the bishops, and each of them in his own diocese was the pre-eminent sacred minister and successor in it to the apostolic ministry.
Church History (Seminary Course) translated by Isaac Lambertson
chapter 28, "Ecclesiastical Administration"
St. John Chrysostom commentary on Acts
p. 54 – 55
For when the Spirit was to be made known to John, then it came upon the head of Christ as in the form of a dove: but now, when a whole multitude was to be converted, it is “like as of fire. And it sat upon each of them.” This means, that it remained and rested upon them.” For the sitting is significant of settledness and continuance. Was it upon the twelve that it came? Not so; but upon the hundred and twenty. For Peter would not have quoted to no purpose the testimony of the prophet, saying, “And it shall come to pass in the last days, saith the Lord 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 they were all filled with the Holy Ghost.” “And it sat upon each of them,” says the writer. Observe now, how there is no longer any occasion for that person to grieve, who was not elected as was Matthias, “And they were all filled,” he says; not merely received the grace of the Spirit, but “were filled. And began to speak with other tongues, as the Spirit gave them utterance.” It would not have been said, All, the Apostles also being there present, unless the rest also were partakers.
“This,” says he, “is that which was spoken by the prophet Joel; And it shall come to pass in the last days.” He shows, in fact, that the consummation is nigh at hand, and the words, “In the last days,” have a kind of emphasis. [“I will pour out,” etc.] And then, that he may not seem to limit the privilege to the sons only, he subjoins, “And your old men shall dream dreams.” Mark the sequence. First sons; just as David said, “Instead of thy fathers, were begotten thy sons.” (Ps. xlv. 17.) And again Malachi; “They shall turn the hearts of the fathers to the children. And on my handmaidens, and on my servants.” (Mal. iv. 6.) This also is a token of excellence, for we have become His servants, by being freed from sin. And great is the gift, since the grace passes over to the other sex also, not as of old, it was limited to just one or two individuals, as Deborah and Huldah.130 He did not say that it was the Holy Ghost, neither did he expound the words of the prophet; but he merely brings in the prophecy to fight its own battle.
Even while the Apostle Peter was reminding his hearers of the prophesy, he wanted to encourage the Gentiles, who knew very well that they were outside the Church, that they too will be invited in the future to join the Church and be welcomed in the Church. Later, this open invitation was confirmed by other signs of those immediate times, such as when the Holy Spirit was given to hearers of the Apostles' preaching even prior to their baptism.
Acts 10:44-4844 While Peter yet spake these words, the Holy Ghost fell on all them which heard the word.45 And they of the circumcision which believed were astonished, as many as came with Peter, because that on the Gentiles also was poured out the gift of the Holy Ghost.46 For they heard them speak with tongues, and magnify God. Then answered Peter,47 Can any man forbid water, that these should not be baptized, which have received the Holy Ghost as well as we?48 And he commanded them to be baptized in the name of the Lord. Then prayed they him to tarry certain days.