Here is a passage from C.S. Lewis' Miracles. The stunning imagery of this, the grand miracle, has stuck with me over the years and is fitting for our Advent consideration.
"In the Christian story God descends to re-ascend. He comes down; down from the heights of absolute being into time and space, down into humanity; down further still, if embryologists are right, to recapitulate in the womb ancient and pre-human phases of life; down to the very roots and sea-bed of the Nature he has created. But He goes down to come up again and bring the whole ruined world up with Him. One has the picture of a strong man stooping lower and lower to get himself underneath some great complicated burden. He must stoop in order to lift, he must almost disappear under the load before he incredibly straightens his back and marches off with the whole mass swaying on his shoulders. Or one may think of a diver, first reducing himself to nakedness, then glancing in mid-air, then gone with a splash, vanished, rushing down through green and warm water into black and cold water, down through increasing pressure into the death-like region of ooze and slime and old decay; then up again, back to colour and light, his lungs almost bursting, till suddenly he breaks surface again, holding in his hand the dripping, precious thing that he went down to recover. He and it are both coloured now that they have come up into the light: down below, where it lay colourless in the dark, he lost his colour too."