Flesh. Ultimately, this is what Christmas, as a religious holiday, comes down to. Christmas is the Feast of the Incarnation, that is, the en-fleshment of God in Jesus. That is what the Latin root of incarnation means, the being made flesh.
Ever since the event of the Incarnation, ever since God became flesh in Jesus, our flesh has enormous dignity and eternal purpose. God has become flesh so that we can, in the fullness of our being, share eternally in the life of God.
So this Christmas I urge you to be good to your flesh. Try not to overeat. Get enough rest. Go slow on the eggnog and holiday drinks. Eat only two pieces of pie rather than four. Be good to your flesh. Get some exercise (see the list posted below). Let go of stress. Enjoy your flesh. Christmas teaches us that our flesh was worthy of Second Person of the Blessed Trinity. Therefore our flesh has great dignity, and a wonderful, spectacular destiny in the Resurrection. But that is something we celebrate at Easter.
Meanwhile, Merry Christmas!