John introduces the main Character that he will be writing about, laying down pertinent details right away so that we know—at least a little bit—of the length and breadth and depth of this Being. He was God. He is God. He was in the beginning with God. Therefore He was pre-existent. Before there was time, there was God.
Before there was time, there was the Logos. The Logos is the main Character of this story that will unfold. He was God; He was with God; He is the Creator of everything that is. He is the One who gave life to Adam and Eve. He is the Power behind every law, force, and energy that exists. He is the One who was there from the beginning.
John then lays the groundwork so that we understand where he is coming from. He introduces words that will play a great part in understanding this Personage: that He is light, that He is truth, that He is reality in contrast to those things that we call "real"—at least physically real—but they are not eternal. They are not age-lasting as He is.
