While you have the light, believe in the light so that you may become sons of light.” Jesus said this, then went away and hid from them.
It is faith that makes one a ‘son of the light’. Jesus is the Light and He calls us to believe. Through believing we are reckoned as children of the Light. By faith we are those who walk in the light as He is in the light rather than those who grope in the darkness. We walk by faith and not by sight.