Today is the holy-day set aside to commemorate when the Second Person of the Trinity was conceived by the Holy Spirit of the Virgin Mary. Go here for some fine celebratory material, including YouTubes of Bach performances in which the composer pours out his creativity to celebrate the Incarnation: CyberBrethren-A Lutheran Blog: The Annunciation of Our Lord.
It’s a good day too to reflect on the personhood of the unborn child, with Christ going through the whole process of human development beginning at the moment of His conception.