John 1 " In the beginning was the Word..."    John's purpose in writing this gospel was to reveal who Jesus really is, that we might believe on Him and receive true life.  Every message and every action that John recorded was written for that express purpose.  That we might KNOW Jesus.

The first 5 verses tell us that Jesus is:
The Word
God
The Creator
Life
Light

The Word - "logos" - the divine expression, the divine communication.  He who was with God and was God; Who was with God in the beginning,  came to us.   He was with God, the Father in the creation, John writes, and He was actively involved in all that was created.  " In Him was life.." Life does not just come into being on its own,  it is not an evolution started by a random mix of chemicals.
Life has a source, a creator.  And that is Jesus, the Eternal Word.

His life is "light".  Luminousness - God said, "Let there be light".  When the earth was dark and void of life and form.. God spoke - and Light was the first thing He added in order to establish life.  Light is essential to life.  Jesus  is essential to life and to light..  He came to shine in the darkness - physically in the creation of the earth and spiritually as the Son of man and of God.

Yet darkness does not comprehend light.  It tries to seize and obscure and possess light, but it can not overcome light.  Light will always win!  Praise God!

Father in heaven, You are light and  "in YOU is no darkness at all." ( John wrote).  And  James wrote, " Every good thing... is from above coming down from the Father of lights, with whom there is no variable, or shifting shadow."  Perfe