At Christmas, the Divine Word became flesh. Blasphemy to the Jews, foolishness to the Greeks, and sedition to the Romans, but it happened all the same. The very fact that such a thing is even possible demonstrates the central promise of Christianity: that we human beings, just as we are, can partake of the divine nature, just as it is, without any fudging, equivocation, or dismal compromises. Any and all of the resources of heaven—whatever you might need to face the challenges of your life—will fit into a human being.
We know this, because it has already happened.
And when Jesus proved it possible, He also invited you to join Him in the dance. Want in? Ask, and it will be given to you, like the Man said.
Axial tilt is the reason for the season, but the incarnation of God is the reason we celebrate.