A couple of good posts on sharing your faith, on Christmas or any time:
Russell Moore gives a few quick thoughts on what followers of Jesus ought to remember, especially if you’ve got a difficult extended family situation: peace, honor, humility, maturity and perspective. Some of them aren't quite so quick, but it's well worth the time to read his thoughts.
Chris Castaldo (who recently published a book on ministering to Catholics that I am currently reading) unpacks this statement: “Evangelism is the activity in which the entire Church prayerfully and intentionally relies on God in sharing gospel love and truth, in order to bring people one step closer to Jesus Christ.”
Praying we'll bear witness to Christ in both word and deed this Christmas (and every day!).