1 John 2:11
 But whoever hates his brother is in the darkness and walks in the darkness, and does not know where he is going, because the darkness has blinded his eyes. (ESV)
The other day I had my eyes examined. The eye doctor had a bunch of normal questions that she asks every patient. One of them was, "Do you have any problems with night vision." I responded that I did not. And by my answer I meant that I do not have any more problems with night vision than anyone else would. The fact is we all struggle with night vision.
The darker it is the harder it is to see. I am no scientist, but I think you can agree with me on this one. Most of us do not encounter real darkness. Total absence of light is not something that we get very close to. We may turn out the lights and go to bed yet still have star/moonlight outside of our window giving some light. If we had to live in complete darkness it would be extremely difficult to function.
The Apostle John is very concerned with how we function as believers in Jesus Christ. He tells us that the idea of hating your brother and attempting to walk in a proper direction is as impossible as a person in total darkness trying to walk in such a way as to have any idea where he is going.
Hatred is a monstrous thing. It is not content to just affect one situation. It overwhelms us. It goes from darkening our understanding to completely blinding us. I have seen this sad reality in people many times. Church members who have heard the truth and even preached it to others have become consumed with blinding rage and lost all their ability to live a godly life.
Are you entertaining a hateful attitude? Be careful. You will go from dim vision to complete spiritual blindness very quickly. Hatred brings blindness. Lord Jesus, open our eyes to your love. Forgive us for our hatred.