In verses 3-5 John shares the impact the Word had and has on and in the world which He has created.  And gives  us two more layers to peel away that reveals Jesus Christ as 'Life & Light'. 

Scripture References:

Colossians                 1:16
John                              1:3-5
John                             10:10
John                             14:6
Matthew 4:16       21:23
John                            3:17-21