Andrew Peterson - Behold The Lamb
The title song from a musical written by Andrew Peterson that he has been performing live for many years. My church used the songs from this musical for our Christmas presentation, although it's not Christmas music per se. But it tells the story of the events leading up to the birth of Jesus, so it worked really well.
The song was co-written by Laura Story.
"Behold the Lamb of God, who takes away the sin of the world." - the words of John the Baptist from John 1:29.