The Son was sent, but the entire Godhead was still present in Christ. What part of Divinity stayed "behind"? It is a mystery on exactly what happened at the Incarnation. Only the Logos became flesh, but the entire Godhead became flesh because within the Logos is the entire Godhead. Unless you believe in three Gods.
Regards
What are you doing messing with this? You should be enjoying the day and your family. We have plenty of time to discuss this right after the Cowboy's game.
Merry Christmas jo.
Howard