But he who hates his brother is in the darkness, and walks in the darkness, and doesn't know where he is going, because the darkness has blinded his eyes.

 It is the simple fact of the Christian life that things would be different at once if we would only put into practice what we already know. That is not to say that we never need to learn anything new; but it is to say that, even as we are, we have light enough to walk by if we would only use it. 