In Matthew 16, when Peter confessed that he believed that Jesus was the Christ, the son of God, Jesus spoke about a rock upon which he would build his church, and he said that the gates of Hell would not prevail against it.
Whenever I heard that verse as a young person, I had in my head the thought that somehow the church was in danger from those scary hell-gates, but, nevertheless, Jesus was saying that the church will manage to survive the onslaught.
I don’t think that way anymore, but it took me a long while to see things differently.
In the ancient world, city gates were designed as a protective mechanism. They were used to let people who were friendly to the city in and out of the city. They were also designed to keep the city’s enemies on the outside and prisoners inside. The gates did this by not opening for the enemy, and as long as they withstood the enemies attacks (by not falling apart), they did their job.
Never in the history of the world – as far as I know – have city gates attacked anyone. Never have city gates gone on a rampage through the countryside terrorising the inhabitants. (OK, one set of gates did go off through the bush, but that was only because Samson was carrying them).
Gates are for defence, not attack. So when Jesus says that the gates of Hell will not prevail against the church (or the rock upon which it is built), then he is saying that the gospel message will be effective in its attack upon the kingdom of Satan. It is Satan’s kingdom that in under threat.
The gospel of Jesus Christ – his life, death and resurrection – is a message of liberty. But it does not bring freedom to people who are good. The gospel is for rebels who had rejected the word of God. They were in darkness; they were imprisoned by sin, death and Satan (Psalm 107:10-11), but God humbles such people and brings them to faith in Jesus Christ. In this way are the gates of bronze burst, and the city taken. Psalm 107:16 says the Lord “has broken the gates of brass, and cut the bars of iron in two.” He does this to release prisoners and to set captives free.
The church militant is to go forward with the good news of Jesus.