A portion of Martin Luther's Christmas sermon, 1530. (Here is the piece in its entirety: http://mail.mcm.edu/~eppleyd/Luther2.html ) Good things to think about!
"Take yourself in hand, examine yourself and see whether you are a Christian! If you can sing: The Son, who is proclaimed to be a Lord and Savior, is my Savior; and if you can confirm the message of the angel and say yes to it and believe it in your heart, then your heart will be filled with such assurance and joy and confidence, and you will not worry much about even the costliest and best that this world has to offer. For when I can speak to the virgin from the bottom of my heart and say: O Mary, noble, tender virgin, you have borne a child; this I want more than robes and guldens, yea, more than my body and life; then you are closer to the treasure than everything else in heaven and earth, as Ps. 73 [:25] says, “There is nothing upon earth that I desire besides thee.” You see how a person rejoices when he receives a robe or ten guldens.
"But how many are there who shout and jump for joy when they hear the message of the angel: “To you is born this day the Savior?” Indeed, the majority look upon it as a sermon that must be preached, and when they have heard it, consider it a trifling thing, and go away just as they were before. This shows that we have neither the first nor the second faith. We do not believe that the virgin mother bore a son and that he is the Lord and Savior unless, added to this, I believe the second thing, namely, that he is my Savior and Lord. When I can say: This I accept as my own, because the angel meant it for me, then, if I believe it in my heart, I shall not fail to love the mother Mary, and even more then child, and especially the Father. For, if it is true that the child was born of the virgin and is mine, then I have no angry God and I must know the feel that there is nothing but laughter and joy in the heart of the Father and no sadness in my heart.
"For, if what the angel says is true, that he is our Lord and Savior, what can sin do against us? “If God is for us, who is against us?” [Rom. 8:31]. Greater words than these I cannot speak, nor all the angels and even the Holy Spirit, as is sufficiently testified by the beautiful and devout songs that have been made about it. I do not trust myself to express it. I most gladly hear you sing and speak of it, but as long as no joy is there, so long is faith still weak or even nonexistent, and you still do not believe the angel."