In Him was life, and that life was the light of men

John 1:4 is saying that creative life-giving power comes from Jesus.  That life itself resides in Jesus.  A little later on in John's Gospel we will hear Jesus say, "I am the resurrection and the life."  It is hard for us to see the one on one correlation between life itself and Jesus himself.  What does it mean that Jesus gives life?  I think that God has necessarily brought about the existence of Jesus because of the very nature of life itself, but what does it mean?  John adds the application at the end of verse 4, "and that life was the light of men."  Jesus' life is the thing that provides spiritual illumination, understanding, comprehension, or in our modern language: good information about God. This is profound, it means that the life of Jesus is the source of spiritual information for everyone.  This isn't such a far fetched exclusivist idea as you would think, because people from many religions have a place for Jesus somewhere, as a great prophet, a holy man, or other things.  Even so, to have true spiritual understanding one cannot ignore, but rather must accept, Jesus' own self-disclosure that was so clearly preserved in the Gospels. Spiritual darkness doesn't necessarily mean that a person has no knowledge about God, or has not heard some really good information about God.  Spiritual darkness can be like a dark cloud of circumstance that envelops our life, that hangs over our head like a blanket, so that we neither see, nor even breathe!  An understanding and acceptance of Jesus will dispel this.  A realization and communion with the Lord will pull the blanket from our head.  Coming to Christ is like coming out of the spiritual fog, out of the darkness.  But, with John's Gospel, we sometimes see that "the light shines in the darkness, but the darkness has not understood it."