This song is aptly titled, as it acted as a guiding light to the Now, Then & Forever album. Vocalist Philip Bailey told Billboard magazine: "When we got finished with that song someone mentioned to me that it sounded like a great Earth, Wind & Fire that people had missed all these years. Then I started listening to the music we had done to that point, and the 'Guiding Lights' song made me rethink the music we had and I said, 'We've got to go back to the drawing board to make these other songs more classic sounding' and just changed the whole course of the album."
This is one of six songs on Now, Then & Forever that was co-written by Bailey's son Philip D. Bailey.
Carla Thomas became the first woman to achieve a Top 10 hit on the Hot 100 with a song she wrote herself when "Gee Whiz (Look At His Eyes)" reached the chart's top tier in 1961. Thomas was just 16-years-old when she penned it.
The lyrics for "Mary, Did You Know?" were written by Christian singer and comedian Mark Lowry, after his pastor asked him to write a Christmas musical for their church. Southern gospel musician Buddy Greene later added music to his words.