"Nothing makes an enemy more dangerous than the fact that he remains hidden or forgotten. Of the three great enemies of the Christian--the world, the flesh, and the devil--the last is the most dangerous. Not only because it is he who lends the others what power they have, but also because he is not seen and, therefore, little known or feared. The devil has the power of darkness. He darkens the eyes, so that men do not know him. He surrounds himself with darkness, so that he is not observed. Yes, he even has the power to appear as an angel of light. It is by the faith that recognises things unseen that the Christian is to endeavour to know Satan--even as the Scriptures have revealed him.