Christine Young - Go Light Your World (a Chris Rice song). Says YouTube user Bob Marsahll, who posted this version:
Chris Rice wrote this song and also recorded a very nice version of it. Kathy Troccoli also made a nice recording of the song. I like this version by Christine Young the best, though. Wish I could tell you more about Christine but Google didn't cooperate. I do know that the song is from a nice album called "Beauty From Ashes", which was recorded in Germany in 2002. At that time Christine had been singing for over 20 years. The song echoes the sentiments of Matthew 5:16.
LATER (posted to my Facebook timeline Sunday, Sept. 27): A different kind of birthday -- Debi and I joined the praise team at Springfield's new ELCA Lutheran congregation for our first Saturday "contemporary" communion service. (Picture below shows members, in the background, singing at the first blended service incorporating Atonement, Faith and Luther Memorial the week before.) New type of music, new techniques like singing into a mike and reading scripture to keyboard backup, etc., but it went pretty well for a guy who was practically sight-reading!