The Keys Given to Peter
The question
Why do Catholics make such a big deal about Peter getting some keys?
Scripture · Matthew 16:19
I will give you the keys of the kingdom of heaven, and whatever you bind on earth shall be bound in heaven, and whatever you loose on earth shall be loosed in heaven.
A short answer
It sounds like an odd thing to build a papacy on — Jesus hands one guy some keys, and suddenly there's a 2,000-year office? But the imagery isn't random, and a first-century Jew would've caught it instantly. Jesus is quoting Isaiah 22, where God removes a corrupt royal steward and gives his authority to Eliakim: "I will place on his shoulder the key of the house of David; he shall open, and none shall shut; and he shall shut, and none shall open" (Isaiah 22:22).
That steward was the prime minister of the kingdom — the man who ran the house when the king was away, an office that passed from one holder to the next. So when Jesus, the Son of David, gives Peter "the keys of the kingdom" and the power to bind and loose (Matthew 16:19), He's installing a steward for His Church. Not a replacement for the King, but a visible authority acting in His name. The Church sees this as the foundation of the papal office (CCC 553, 881).
Notice what changes: only Peter gets the keys, only Peter gets renamed "Rock," only Peter is told the Church will be built on him. Jesus could've shared leadership evenly. He chose, very deliberately, to give one man a stewardship — and stewardships, by their nature, get handed on.