Today, the world recognizes that it is the 2009th year of our Lord. For the Church, the year came with Christmas, as it intended to be an anniversary count. Every liturgical calendar begins on Christmas day.
For the Christian world, today we think of the circumcision of Jesus (as he was born to Jewish parents, circumcision comes on the eight day.) Today one thinks of the humanity of Jesus — how he went through the customs of being a man.
It is also a day when we remember the title given Mary “Theotokos”, literally God bearer, and rendered by the Roman Catholics as Mother of God. This was to recognize that the baby itself was divine — and was not somehow united with Divinity at some other time.
Today is a day to think about Theology, and how one can be God and Man at the same time. Even if at that moment he lives under the limitations of an infant.