Summary: A study of the impact of Jesus as light in our darkened world.
“Jesus cried out and said, ‘Whoever believes in me, believes not in me but in him who sent me. And whoever sees me sees him who sent me. I have come into the world as light, so that whoever believes in me may not remain in darkness. If anyone hears my words and does not keep them, I do not judge him; for I did not come to judge the world but to save the world. The one who rejects me and does not receive my words has a judge; the word that I have spoken will judge him on the last day. For I have not spoken on my own authority, but the Father who sent me has himself given me a commandment—what to say and what to speak. And I know that his commandment is eternal life. What I say, therefore, I say as the Father has told me.’” 
For almost 150 years, Christians have sung the hymn, “The Light of the World is Jesus.”  For almost two millennia before the hymn was written, followers of the Christ knew that He was the light of the world; the song merely put into lyric form the faith of the faithful. It is difficult for us to imagine a world in which we could know neither the love of God nor enjoy walking in the light of Christ the Lord. Or is it?
John opens the Gospel that bears his name by writing words we recognise immediately, “In the beginning was the Word, and the Word was with God, and the Word was God. He was in the beginning with God. All things were made through him, and without him was not any thing made that was made. In him was life, and the life was the light of men. The light shines in the darkness, and the darkness has not overcome it.
“There was a man sent from God, whose name was John. He came as a witness, to bear witness about the light, that all might believe through him. He was not the light but came to bear witness about the light.
“The true light, which gives light to everyone, was coming into the world. He was in the world, and the world was made through him, yet the world did not know him. He came to his own, and his own people did not receive him. But to all who did receive him, who believed in his name, he gave the right to become children of God, who were born, not of blood nor of the will of the flesh nor of the will of man, but of God” [JOHN 1:1-13].
In this prologue of the Gospel of John, the Word, Jesus the Son of God, is identified as “the True Light.” Jesus is identified as very God in human flesh in this passage. This Jesus was the unique God-man—there was no other like Him, nor shall there ever be another like Him. To be certain, He took upon Himself the sin of mankind, providing an infinite sacrifice for fallen mankind; but more than that, the Living Saviour has shed light into every corner of our existence so that we no longer need to live in darkness.
BELIEVE? IN WHOM? Words matter! Promises matter! What is promised is important, and the more so when the promise has an impact on our eternal destiny. I have heard people ask how to believe. John wrote, “To all who did receive him, who believed in his name, he gave the right to become children of God” [JOHN 1:12]. John equates receiving with believing—to receive Jesus is to believe Jesus. He must be the Master over life if He is to be Saviour of an individual.
It is essential for us to realise that God, through His Word, promises to give to a select group of people what He has identified as “eternal life.” Eternal life, God’s salvation, is not distributed to all mankind, but only those who receive it by faith. Those people to whom this divine gift is given are those who receive as Master over life the One whom God sent to deliver them. The eternal life God has promised is not merely endless length of days, though it does refer to an absence of death; eternal life speaks of a quality of life, a new existence based upon an everlasting relationship to God who is life. This new quality of existence is found only in Christ as Master, as emphatically and repeatedly promised throughout the Word of God. Eternal life, that new relationship with God who is life, is reserved for those who accept the Son of God as Master over life. He takes up residence in the individual’s life, and His presence ensures the new relationship with God.