Acts 2:14-18
14 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.
15 For these are not drunk, as you suppose, since it is only the third hour of the day.
16 But this is what was spoken by the prophet Joel:
17 ‘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.
18 And on My menservants and on My maidservants I will pour out My Spirit in those days; And they shall prophesy.
According to the Prophet Joel and the Apostle Peter, the primary manifestation and fruit of a Spirit-filled church is prophesying.
In the New Testament, prophesy - usually of forth telling which reveals the mind (message) of God in a particular situation; can also refer to foretelling, i.e. predicting the future as the Lord reveals it.
The essence of the word is that of “speaking the word of God under the inspiration of God.”
So “the church that the gates of hell cannot prevail against” is a prophesying church that is releasing the salvation and power of the gospel of the kingdom of heaven upon earth by speaking forth anointed words though speaking, preaching, singing, praying, etc.
Dynamics of Prophesying
John 6:63 (NKJV)
63 It is the Spirit (pneuma) who gives life (zoe root); the flesh profits nothing. The words (rhema) that I speak to you are spirit (pneuma), and they are life (zoe).
John 6:63 (NIV)
63 The Spirit gives life; the flesh counts for nothing. The words I have spoken to you—they are full of the Spirit] and life.