We say it's the "Christmas story", but in fact, it is sharing the Word of God when we share that "story". When I began to seriously read Matthew 1 & 2 and Luke 1 & 2, God began to show me things that I never noticed before. Since it is such a familiar portion of Scripture, we tend to read it without really reading it, just like I was singing God's Word without being aware of it.
Advent is a time of expectation of the coming of the Savior. May I suggest that you use the days of Advent to experience the expectation of His coming deeper into your life. Read those 4 chapters asking God to show you something new. He'll meet you there! And then you'll have something to share!