And Jesus answering said to him: "And I say to thee: That thou art Peter; and upon this rock I will build my church, and the gates of hell shall not prevail against it. And I will give to thee the keys of the kingdom of heaven. And whatsoever thou shalt bind upon earth, it shall be bound also in heaven: and whatsoever thou shalt loose on earth, it shall be loosed also in heaven." (Matt. 16:18-19)
THE DURATION OF THE CHURCH: "The gates of hell shall not prevail against it." The Church, therefore, can neither be overcome nor destroyed; it will endure till the end of time.
[From 'A Practical Commentary on Holy Scripture' by Bishop Knecht, D.D.]
(1899 Douay-Rheims Bible)