John 12 (NASB)

"While you have the light, believe in the light, in order that you may become sons of light." (John 12: 36) 

Jesus is our light (John 8:12) He is the light of this world, and while He is available to us, we must believe in Him so that we can become His sons and daughters.  Whether we want to or not, "Every knee shall bow and every tongue will confess." (Romans 14:11)  So, might as well take advantage of it now and believe in the LIGHT now so that we won't be left of our inheritance as sons and daughters.