Replacing the Shadows

Now the point in what we are saying is this: we have such a high priest, one who is seated at the right hand of the throne of the Majesty in heaven, a minister in the holy places, in the true tent that the Lord set up, not man. (Hebrews 8:1–2, ESV) 
The point of the book of Hebrews is that Jesus Christ, God’s Son, has not just come to fit into the earthly system of priestly ministry as the best and final human priest, but he has come to fulfill and put an end to that system and to orient all our attention on himself ministering for us in heaven.
The Old Testament tabernacle and priests and sacrifices were shadows. Now the reality has come, and the shadows pass away.
Here’s an Advent illustration for kids (and for those of us who used to be kids and remember what it was like). 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 seeing that it’s really her?
That’s the way it is when Jesus comes to be our High Priest. That’s what Christmas is. Christmas is the replacement of shadows with the real thing.
John Piper, Good News of Great Joy: Daily Readings for Advent, p. 25-26