I’m sure we could draw up a list of answers to that question, but underlying them all is one bigger answer. It’s something called: Chalcedonian Christology.

You probably think, “what on earth is that?!”. I know it’s a mouthful. Don’t worry: it’s not a phrase you need to learn, but it refers to the Chalcedonian Creed, which is a creed written in 451 AD in Turkey (you can read it here). Very simply, in the Chalcedonian Creed, the church confessed how the Godhead and the manhood of Christ relate together.

The answer the church gave was something that the typical man finds hard to do! They said: when it comes to Christ, you have to think two thoughts at the same time. Now, being a man, I find that hard to do! My brain struggles to handle lots of thoughts at the same time! But this ability is what the Chalcedonian Creed wants to teach us and is at the heart of all good Christmas carols.

Here are the two thoughts:

Thought 1. The identity of this person is “God of God, Light of Light”. In other words, Jesus is the only begotten Son, without beginning and without end. He’s not to be confused with the Father or the Holy Spirit, but together with them is to be worshipped and glorified, as the one true God. This is why Thomas says to Jesus: “My Lord and my God!” (John 20:28). This is why the wise men fell down and worshipped him (Matthew 2:11). This is why the angels are commanded to worship him (Heb 1:6).

Thought 2. This Son becomes true man. He unites to himself a real human body, with specific DNA and a genome. He takes to himself a real human soul, with a mind, and emotions and feelings. This real human being was conceived in the womb of the virgin Mary. He was born in the ordinary way. He developed normally through infancy and toddler years, learning language by listening to his parents, learning to sit up and walk (Luke 2:40, 52). This true man is weak, needy, and dependent. This is why he could say: “The Father is greater than I” (John 14:28).

Chalcedon teaches us that we have to think these two thoughts together when we think of Christ. In other words, thought 2 doesn’t cancel out thought 1, or replace it. Jesus’ Godhead isn’t lost or watered down by his manhood. The two go together at the same time.

I know it’s possible to talk about Jesus like we’re dissecting a frog. We can dissect his two natures, like a frog’s anatomy, which is all very interesting, but the frog is dead! But, Chalcedonian Christology isn’t doing this. It’s more like a science experiment in which you take a plastic film canister and half fill it with water. You then put an Alka-Seltzer tablet inside the film canister, quickly put the cap on, and place it top-side down on the ground while backing away. The result should be an explosion, in which the film canister turns into a rocket and launches into the sky! When you put the water and the Alka-Seltzer tablet together they create an explosion. Chalcedonian Christology is like that. Put those two thoughts about Christ together and you have some rocket fuel! The Godhead of Christ alone isn’t enough. The manhood of Christ alone isn’t enough. It’s the two combined, in one person, without confusion or separation, that produces cracking Christmas carols, that really take off.

So, for example, watch how Charles Wesley puts the two natures of Christ together in his Carol: “Glory be to God on high”

Glory be to God on high,

and peace on earth descend:

God (Thought 1) comes down (Thought 2), He bows the sky,

And shows himself our friend:

God the invisible (Thought 1) appears (Thought 2):

God, the blest, the great I AM (Thought 1),

Sojourns in this vale of tears (Thought 2),

And Jesus is his name”




Him the angels all adored,

Their maker and their king; (Thought 1)

Tidings of their humbled (Thought 2) Lord (Thought 1)

They now to mortals bring.

Emptied (Thought 2) of his majesty (Thought 1)

Of his dazzling glories (Thought 1) shorn (Thought 2),

being’s source (Thought 1) begins to be (Thought 2),

and God himself (Thought 1) is born! (Thought 2)




See the eternal Son of God (Thought 1)

a mortal Son of Man; (Thought 2)

dwelling in an earthly clod (Thought 2),

whom heaven cannot contain (Thought 1).

It’s that explosive combination of Chalcedonian Christology that makes good Christmas carols. Training yourself to think these two thoughts about Jesus at the same time will greatly add to your desire to worship him.