John 12:35-36 Jesus replied, "My light will shine out for you just a little while longer. Walk in it while you can, so you will not stumble when the darkness falls. If you walk in the darkness, you cannot see where you are going. Believe in the light while there is still time, then you become children of the light."
Darkness is coming. God doesn't promise to always shine His Light on the world or our lives. He is very patient and will let Him shine as long as He can, but there will come a day in which His patience with us will end. He doesn't want any of us to die in our sins, so He continues to let His Light shine. The issue then is how we respond to the Light. Some of us walk in the Light, while others choose to walk in the darkness. In the darkness you will never keep up with or follow those who walk in the Light.
Some are standing around in the glow of the Light, waiting to get on board. What they fail to accept or acknowledge is that the Light is not standing still with them. The Lord is always on the move and the longer we stand around, the dimmer His light is. We can wait around to longer and no longer see the Light.
The assumption is that the Light will always be there for us to come to whenever we want to. He won't be. The Lord is always on the move and only those in step with Him will be able to stay out of the darkness. He is moving towards Judgment Day. The Lord is leading His children forward, preparing them for their encounter with God. Only those who are in the Light will be ready.
Walk in the Light while you can. Don't let the Lord move on without you. Don't be among those left behind because they are in the darkness and can't find their way. It's not too late, but it soon will be if you delay. Don't let the darkness snuff out any light you may have.