In a sense, our Lord laid aside his glory to take on human nature. Yet, paradoxically, in this act of self-emptying he revealed the life of the Godhead - the glory of God. How? Because the glory of God is his very life of self-emptying love the exists between the Father, the Son and the Holy Spirit. So by becoming man, the only begotten Son revealed the glory of God.
At the same time, by becoming man - by forming what theologians call the theandric union - he made all that God has made share in the glory of God. This is our destiny as humans - to be fully united with God so that his glory may become our glory.
What an amazing God! He is glorified; we are glorified and all because of his holy and loving will.
felix dies Nativitatis!