One of the best ways to do this is to let them see what Christmas means to you and your family. And one of the best ways to do that is to include them in some special event with your family during this season of the year.
For example, you might invite them and your other neighbors over for an open house, and include some carols and perhaps a reading of the Christmas story from the Bible. Or you might invite them to a special Christmas concert at your church or in your community. Even if they are unable to go, they will sense your concern for them and realize that Christmas has a special meaning for you.
The most important thing you can do, however, is to pray for your neighbors. Pray that they will begin to see the emptiness of their lives and realize they need the meaning and purpose only Christ can give. Pray also for an opportunity to share what Christmas means to you–that God sent His Son into the world on that first Christmas to show us His love.
In addition, reach out to your neighbors throughout the year, and not just at Christmas. The Bible says, "Always be prepared to give an answer to everyone who asks you to give the reason for the hope that you have. But do this with gentleness and respect" (1 Peter 3:15).