John Piper gave the following illustration to children and their parents, to explain what Christmas is:

Kids, suppose you and your mom get separated in the grocery store, and you start to get scared and panic and don't know which way to go, and you run to the end of an aisle, and just before you start to cry, you see a shadow on the floor at the end of the aisle that looks just like your mom. It makes you really happy and you feel hope. But which is better? The happiness of seeing the shadow, or having your mom step around the corner and it's really her!? That's the way it is when Jesus comes to be our [Savior]. That's what Christmas is. Christmas is the replacement of shadows with the real thing.