Summary: Treasure the Keys of the Kingdom 1) Understand what they are 2) Use them faithfully
I bet every adult here carries around a handful of keys. Which of those many keys is the most important to you? Which key would you hate most to lose? The key to your garden shed? The key to your bicycle lock? The key to a suitcase? No, I don’t think you would count any of those keys as the most important. Instead I think you would hate most to lose your car key or house key. That’s because without your car key you can’t get anywhere. And without your house key you have nowhere to end up at. Of course it’s annoying to misplace any kind of key and so if you’re like me, you’re in the habit of patting every pocket before you go anywhere to make sure you have your keys.
As Christians we also possess another set of keys that, while we can’t actually hold them in our hands, these keys are more important than any other key we have. These are the Keys of the Kingdom given to us by Jesus himself and so we will want to treasure them. We do that when we understand what these keys are and when we use them faithfully.
We learn about the Keys in Matthew 16 where Jesus said to the Apostle Peter: “I will give you the keys of the kingdom of heaven; whatever you bind on earth will be bound in heaven, and whatever you loose on earth will be loosed in heaven” (Matthew 16:19). The first part of that verse is simple enough. Jesus is giving Peter, as the spokesman of the apostles, keys to the kingdom of heaven. But what does it mean that these keys can bind and loosen things on earth and in heaven? The sixteenth century reformer, Martin Luther, explains when he wrote in his catechism: “The use of the keys is that special power and right which Christ gave to his church on earth, to forgive the sins of the penitent sinners, but to refuse forgiveness to the impenitent as long as they do not repent.”
Luther’s explanation is confirmed when you consider our sermon text from Matthew 18. There Jesus told all of his disciples, and not just Peter, what they were to do if a fellow Christian was caught in a sin. They were to first and go and speak to that individual privately about his sin and call him to repentance. To repent of sin means to be sorry for the sin, to stop committing that sin, and to trust that Jesus has forgiven the sin. If the individual refuses to repent, then the disciples were to “bind” the sin to the individual. That’s kind of what a police officer does when he pulls over a speeder and gives him a ticket. That ticket binds the infraction to the driver so that he has to answer for it in court or by paying a fine. He can’t just drive away and act as if nothing has happened. In the same way when we say to an impenitent that his sin is still bound to him, we’re announcing that he’ll have to answer for his sin on Judgment Day as long as he remains impenitent.
On the other hand, if the sinner repents and says he’s sorry and expresses his trust in Jesus’ forgiveness, then we are to “loose” the sin like untying a boat on a river so that it floats downstream and out of sight. Loosing sin is just another way to say that the transgression has been forgiven and has floated out of God’s sight.