In Him was life, and the life was the Light of men. The Light shines in the darkness, and the darkness did not comprehend it. There came a man sent from God, whose name was John. He came as a witness, to testify about the Light, so that all might believe through him.
-John 1:4-7

In Christ was life. He is the source and giver of all life. Nothing that is in existence would be in existence without Him, for all things were created through Him. Christ did not receive or inherit life, but has always had life and is the provider and possessor of all life. Regarding “and the life was the Light of men,” John Gill writes:

“…all his elect are dead in trespasses and sins, and cannot quicken themselves. Christ has procured life for them, and gives it to them, and implants it in them; a life of sanctification is from him; and a life of justification is upon him, and of faith is by him; all the comforts of a spiritual life, and all things appertaining to it, are from him, and he maintains, and preserves it.”
-John Gill

The light shines in the darkness. The better translation would be “the darkness did not overcomethe” Light. In this context, darkness represents anything that sets itself against the One who gives all life. Darkness is the opposite of light. But just as when a candle is set ablaze in a pitch black cave, so the Light, the Christ, cannot be overcome by darkness.

A man was sent from God, John the baptist. God fulfilled His purposes through this man. He was saved through God’s grace and filled with the Holy Spirit while yet in his mother’s womb (Luke 1:15). It is said that he came to testify about the Light, so that all men might might see the life that the Light brings into a world infested with darkness.

Christ is the one who overcomes the darkness. Thus as Christians we are called to be as John, testifiers of the Light. The Gospel is the Light that overcomes the darkness. As Christians filled with the Spirit we possess the only message that brings life and extinguishes the darkness. How ignorant we are when we put a lampshade over the Light and ashamedly mumble the one message that brings hope and light to the world.