C.S. Lewis called the incarnation “the Grand Miracle.” He wrote this:
“The central miracle asserted by Christians is the Incarnation…. Every other miracle prepares for this, or exhibits this, or results from this…. It was the central event in the history of the Earth—the very thing that the whole story has been about.
“He comes down; down from the heights of absolute being into time and space, down into humanity; down further still … (to) the womb … 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.”
Source: Miracles by C.S. Lewis, chapter 14