“Jesus is the reason for the season” makes for nice Christmas cards and cute home decor. But it doesn’t get the Lutheran view of the Incarnation quite right.
Jesus didn’t come to earth for Himself, because He had nothing else to do, because it was heroic, because He’s a good guy.
He came for you.
You are the reason for the season.
You are the reason Christ took on human flesh. You are the reason He located Himself in a specific time, in a specific place, to specific parents with specific names, for a specific reason.
That reason isn’t Him. It’s you.
He’s not the reason for the season. You are.