Each and every one of us has sinned and fallen short of the glory of God. There is none good, not even one. Even if we won't admit that there is a God to whom we are accountable, we can't escape His law that is written on our hearts and the conscience He placed within us that burdens us with the weight of the real guilt we carry. We are helpless to do anything about it, but the wonderful news of the gospel is that God has done what we could not. This is what Christians celebrate and commemorate on Good Friday.
As if the incarnation of our Lord Jesus Christ was not enough, not only did He empty Himself of significance in coming to take upon humanity, but in His humanity He humbled Himself in obedience all the way to death on the cross. The attitude He had when He willingly walked down these steps of condescension is the same mindset His followers are to have in relation to one another. Nothing less than this is the true spirit of Christmas.