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.

 The last hour does not mean a time of annihilation whose end will be a great nothingness as there was at the beginning. In biblical thought the last time is the end of one age and the beginning of another. It is last in the sense that things as they are pass away; but it leads not to world obliteration but to world re-creation. 