Matthew 16:18 And I say also unto thee, That thou art Peter, and upon this rock I will build my church; and the gates of hell shall not prevail against it.
The gates were a place of judgment.
Deuteronomy 16:18 Judges and officers shalt thou make thee in all thy gates, which the LORD thy God giveth thee, throughout thy tribes: and they shall judge the people with just judgment.
Deuteronomy 17:8 If there arise a matter too hard for thee in judgment, between blood and blood, between plea and plea, and between stroke and stroke, being matters of controversy within thy gates: then shalt thou arise, and get thee up into the place which the LORD thy God shall choose;
Zechariah 8:16 These are the things that ye shall do; Speak ye every man the truth to his neighbour; execute the judgment of truth and peace in your gates:
Logically, then the judgments of Hell will not prevail against the church.
(Of course, the rock Jesus was talking about was Himself, specifically the statement of faith that Peter had just made which is the ultimate foundation and confession of the church;
Matthew 16:16 And Simon Peter answered and said, Thou art the Christ, the Son of the living God.
Here is evidence of the rock Jesus speaks of;
2Samuel 22:3 The God of my rock; in him will I trust: he is my shield, and the horn of my salvation, my high tower, and my refuge, my saviour; thou savest me from violence.
Psalm 18:2 The LORD is my rock, and my fortress, and my deliverer; my God, my strength, in whom I will trust; my buckler, and the horn of my salvation, and my high tower.
1Corinthian 10:4 And did all drink the same spiritual drink: for they drank of that spiritual Rock that followed them: and that Rock was Christ.)