Some years ago my son Nathan and I sang a song together in our Christmas Eve service. I can only remember one other time just the two of us sang a duet and that was in South Africa!
This is not a Christmas song, but it addresses the question of just who Jesus was and is. Christian songwriter/musician Larry Norman first recorded this about 50 years ago. Larry is now with the Lord, but during his life did much to rattle the doors of the church, and I have been appreciative of him, his music and his stand since I was a teen. I encourage you to check him out online if you don't know his work.
Anyway, the link to the video is below of "The Outlaw" we did. Not the best recording, so pardon that and my attempt to sing and play. (It was the last time I did such a public thing!).
If you wonder who Jesus was/is, I'd love for you to come to know Him. As the last verse says, "It's time for us to leave", referring to His soon return. Are you ready? I hope so!