The Christmas story is actually two stories woven together.
The first is a very familiar human story of the birth of a baby. The circumstances are difficult, the parents aren’t married; they are far from home as a result of some bureaucratic process imposed from so far on high that the reason for it is totally invisible; they are sleeping in a barn with the animals. Far from easy, but hardly unusual among the billions of births that have occurred in our world.
The second is a story of God working in this world. He, or she, or they (probably the best pronoun since obviously God doesn’t have a gender) – they had been doing this for quite a while. Certainly since the time of Abraham, which we might place at around 4,000 years ago. That was when the people of Israel first became aware of a god, Yahweh as they subsequently came to understand them.
Those people, our ancestors in faith, realized however that God didn’t just appear at that time. God must have been around from the beginning of mankind – however you might wish to measure that. We now know for sure that we descend from one person. Scientists call her mitochondrial Eve, and presumably there was some guy as well. That was about 100,000 – 200,000 years ago.
On further reflection it was clear that God was there at the beginning of creation. Otherwise there would be a pretty obvious question as to who created God. This idea was indeed amazing when creation meant the beginning of this world, one world wrapped with an unchanged cosmos. Now we know it means approximately 14 billion years and a number of suns beyond counting (many more than the grains of sand on the seashore). That’s completely incomprehensible.
Paul reflects on these two stories and how they are linked: “Jesus Christ … descended from David according to the flesh, but established as Son of God in power according to the Spirit of holiness” (Romans 1:1-7). Ahaz in our first reading was another king of Israel, like David and Jesus – a very irritating one who said all the right things but in fact understood nothing about God. Isaiah is frustrated to the point of telling him that despite his messing about, God would fully reveal themself as a human being: “the virgin shall conceive, and bear a son, and shall name him Emmanuel” (Isaiah 7:10-14).
Our gospel rounds things off by telling us that this is just what happened (Matthew 1:18-24). There was a child born who was God with us. Hard to tell which of the stories is the more incredible.