Brothers, as children of God we must be an example to follow for those who have not yet entered the path of truth, the path of Christ. That is why as a light we must enlighten them and teach them that the light of Christ is what makes us see and understand His word.
We are light in a world submerged in darkness and it is for this reason that many can know the Lord, through our testimony. We are and must be a pure example in the Lord for those who are lost.
Ye are the light of the world. A city that is set on an hill cannot be hid.
Matthew 5:14 (KJV)