God is light, and in him is no darkness at all.... If we walk in the light, as he is in the light, we have fellowship one with another, and the blood of Jesus Christ his Son cleanseth us from all sin. 1 John 1:5-7.
(TDG 92.1)
It is the privilege of the Christian to connect with the Source of light, and through this living connection become the light of the world. Christ’s true followers will walk in the light as He is in the light and therefore they will not travel in an uncertain way, stumbling because they walk in darkness. The Great Teacher is impressing upon His hearers the blessing which they may be to the world, represented as the sun rising in the east, dispelling the mist and the shadows of darkness. The dawn gives place to day. The sun, gilding, tinting, and then glorifying the heavens with its blaze of light is a symbol of the Christian life. As the light of the sun is light and life and blessing to all that live, so should Christians, by their good works, by their cheerfulness and courage, be the light of the world. As the light of the sun chases away the shades of night and pours its glories on valleys and hills, so will the Christians reflect the Sun of Righteousness which shines on him.
(TDG 92.2)
Before the consistent lives of Christ’s true followers, ignorance, superstition, and darkness will pass away, as the sun dispels the gloom of night. In like manner the disciples of Jesus will go into the dark places of the earth, disseminating the light of truth until the pathway of those in darkness shall be illuminated by the light of truth.
(TDG 92.3)
In what contrast to this is the life of the professed child of God who is as the salt without the savor. He has no vital connection with God and, like the worthless salt—which Christ describes as being thenceforth good for nothing but to be cast out and trodden under foot of men—he has no saving properties. Thus is the life of a professed follower of Christ if he has not a living connection with Jesus Christ. These sunless professors are shadows of darkness....
(TDG 92.4)
Every expression of doubt strengthens unbelief. Every thought and word of hope, courage, light, and love strengthens faith and fortifies the soul to withstand the moral darkness that exists in the world. Those who talk faith will have faith, and those who talk discouragements will have discouragements. By beholding we become changed.—Letter 16, March 24, 1880, to a General Conference officer.
(TDG 92.5)