And so I say to you, you are Peter,
and upon this rock I will build my Church,
and the gates of the netherworld shall not prevail against it.
I will give you the keys to the Kingdom of heaven.
Whatever you bind on earth shall be bound in heaven;
and whatever you loose on earth shall be loosed in heaven.
– Matthew 16:18-20
Oh St. Peter! What a wonderful gift you are to the Church. You are a simple, flawed person, chosen by Jesus. He recognized the beauty in you and knew you would be a strong foundation. I wonder what his trust must have meant to you when he said this.
This quote is the basis for the sacrament of reconciliation (confession). Jesus, through St. Peter, gave the authority to share the grace of forgiveness of sins.
This is also the basis for the image of St. Peter as the gatekeeper of heaven.