In the beginning was the Word, and the Word was with God, and the Word was God.As we will see in the next few verses of this first chapter, John is calling Jesus the Word.
(John 1:1, ESV)
In a very real way, that is who Jesus is. He is the perfect revelation of God. (cf. Hebrews 1:1-3) If you want to know God, He must be known through the person of Jesus, because Jesus isn't simply similar to God, He is God (in flesh).
Consider this as you go through this week. God came in flesh to be known by man... and man killed Him.
... but some, only because of the grace of God, believed in Him.