1011 B
I also say to you
This adds emphasis to what Jesus says next.
you are Peter
The name Peter means "rock." (See: rc://en/ta/man/translate/figs-explicit)
upon this rock I will build my church
Here "build my church" is a metaphor for uniting the people who believe in Jesus into a community. Possible meanings are 1) "this rock" represents Peter, or 2) "this rock" represents the truth that Peter had just said in Matthew 16:16. (See: rc://en/ta/man/translate/figs-metaphor)
The gates of Hades will not prevail against it
Here "Hades" is spoken of as if it were a city surrounded by walls with gates that keep dead people in and other people out. Here "Hades" represents death, and its "gates" represent its power. Possible meanings are 1) "the powers of death will not overcome my church" or 2) "my church will break down the power of death the way an army breaks into a city." (See: rc://en/ta/man/translate/figs-metaphor and rc://en/ta/man/translate/figs-metonymy)