"Ye are all the children of light, and the children of the day: we are not of the night, nor of darkness." Paul is speaking of "light" as understanding the teachings of Christ Jesus.
In the book of John, chapter 12, Jesus said, "Yet a little while is the light with you Walk while ye have the light, lest darkness come upon you: for he that walketh in darkness knoweth not whither he goeth. While ye have light, believe in the light, that ye may be the children of light.
….He that believeth on me, believeth not on me, but on him that sent me….And he that seeth me seeth him that sent me. I am come a light into the world, that whosoever believeth on me should not abide in darkness….I know that His commandment is Life everlasting."
As I read and study the Bible and Science and Health with Key to the Scriptures, I think of "Light" as unfoldment of understanding and just as the light of the sun is always shining, if we are listening, our understanding of man's relationship to God is always connected just as stated in Genesis One. God created man in His image and likeness and it is "GOOD." There is no duality in that statement. So when we look to God in every way, follow the teachings of Christ Jesus, and let our light shine, we "can do all things through Christ which strengtheneth me." Strengthen us to understand the healing power Christ teaches us. He even promised us "Eternal Life."
My inspiration here is from Mary Baker Eddy's poem: "LOVE" she writes (4th and 5th verses)
"Through God, who gave that word of might
Which swelled creation's lay:
"Let there be light, and there was light."
What chased the clouds away?
Twas Love whose finger traced aloud
A bow of promise on the cloud.
Thou to whose power our hope we give,
Free us from human strife.
Fed by Thy Love divine we live,
For Love alone is Life;
And life most sweet, as heart to heart
Speaks kindly when we meet and part."