Non-believers attend candlelight services - this provides a great opportunity to explain the Gospel. Christmas Eve is important because of the anticipation of Christmas - only one night away.
If you have family members who don't know Christ, use your church's Candlelight, Easter, New Year's, Mother's Day, Father's Day, Veteran's Day, Fourth of July - special holidays throughout the year can be springboards to sharing the Gospel. Folks enjoy coming to something special - Jesus came today in Bethlehem for lost people to know God.
Last month I was in at the Kentucky Baptist Convention's Crossover evangelism training, and the executive director, Todd Gray, shared an important conversation principle - "As long as someone's listening, you continue talking with them about Jesus." What he means, our best conversations are those about Christ, we want to continue sharing and allow God to speak to listeners - you never know what God is doing in someone's life.
Related Post:
How to Share Christ with your Family this Christmas