An illustration I’ve found helpful is to think about a gift that someone gives you, which is a paying off of a debt. I owe my friend £100, and he says, “You know what, I’ll write off that debt. You no longer owe me £100. And you know what, too? I’m going to give you another £100 as a gift because I know that you could really do with it.” So he gives me the money, cancels my debt, and says, “This is for you.”
Well—knowing all that—can you imagine how strange it would be if I turned around and slapped him in the face in response to that gift he gave me—his cancelling of my debt and his helping me financially? If I just slapped him around the face, it would make no sense. So that’s another helpful picture of what it might look like for a Christian to sin. If your debt has been cancelled and you’ve been given the gift of righteousness, then why would you turn around and insult your saviour by sinning against him?
Another helpful image I find is from the book of Proverbs, which is in reference to a dog. What happens one day is that the dog eats some chocolate—finds some chocolate in the house—and it’s bad; it’s bad when a dog eats chocolate. The owners don’t know that the dog’s eaten chocolate, but suddenly, thankfully, before the dog dies, the dog starts retching. Suddenly, on the kitchen floor, there’s a big pile of vomit—dog vomit—and it’s disgusting. Lots of attention is paid to the dog, and it’s okay. But before you realise it, you turn around, and before you have a chance to clean up the vomit, the dog is going over to the vomit and starts licking it up. You yell, “Get away from it! What are you doing? That just came out of you! The chocolate made you sick, and now you’re licking it up again?” Solomon shows us that that’s what it’s like when we sin. The thing that we have repented from—the thing that we’ve got out of our lives—we go back to it. It makes no sense.
