Our Scripture reading today is Matthew 5:14-16.
Verse 16, "Let your light so shine before men, that they may see your good works, and glorify your Father which is in heaven."
The light that we have to shine before men was given to us when we trusted Jesus Christ as our personal Saviour.  Jesus is the light that shines in and through us.  The hope and help for this dark world we live in is Jesus Christ.  It is our privilege to shine the light He has provided for us.  In order to keep our light shining brightly, we need to guard our steps every day.  My life should be moving further away from the world He saved me out of.  My life should be separated from the world and unto Jesus Christ.  The world in me will dim the light which means my influence will be dimmed.  
God made such a difference in our lives at salvation that the world will see it and wonder what has happened to the person they used to know.  Our testimony of light is not to point people to ourselves, but to our loving, Heavenly Father.  This is why Satan tries so hard to blow out our light.  While he cannot take away our salvation, he will try everything possible to limit God's glory.
Wherever you live and work, there are countless numbers of people that need to see God's light shining through you.  Keep letting your light shine until Jesus comes!