17 And answering Jesus said to him, ‘You are blessed, Simon Bar-Jona, because flesh and blood did not reveal (this) to you but my father in the heavens. 18 And I say to you that you are Peter, and on this rock I will build my congregation, and (the) gates of Hades shall not prevail against it.
This verse has often been used to support a theology of spiritual warfare. In fact, Jesus is saying something quite straightforward but crucial for the continuation of the community of believers and the success of the message that they proclaimed.
1. ‘Gates of hades’ (pulai hadou) is a semitic idiom for death or proximity to death: cf. Job 38:17; Ps. 9:13; 107:18; Is. 38:10; Wisd. 16:13; Odes 11:10; and 3 Macc. 5:51: ‘(The Jews) cried out in a very loud voice, imploring the Ruler over every power to manifest himself and be merciful to them, as they stood now at the gates of death (pros pulais hadou).’
2. Hades is not associated with the demonic or understood as the dwelling place of Satan. Heb. 2:14 speaks of Satan as the one who has the ‘power of death’, but this is not enough to show that the ‘gates of Hades’ can be a metonymy for the hosts of hell.
3. The verb katiskuō with the genitive is dynamic: it means ‘overpower’, rather than ‘withstand’ (cf. Jer. 15:18 LXX). Therefore, ‘the gates of Hades/death will not overpower the church’. There is no suggestion that the church will or should launch an assault on the powers of death or demonic forces.
Jesus is saying, therefore, that the ‘gates of hades will not overcome the church’. But his point is not that the church must be always on the defensive. What he is saying is that as the disciples undertake a mission that will bring them into conflict with hostile political and spiritual forces, that will put their lives at risk, they can be reassured that nothing, not even death, will ultimately overcome the community that is based on the confession of Jesus as the Christ. The statement is important, therefore, precisely because the church must put itself at risk by going out into the world. This is what Jesus goes on to talk about: he himself would suffer, be killed, and be raised from the dead; but anyone who chose to follow him would also have to take up his cross, lose his life, and be glorified with the Son of man (16:21-28).