A definition of insanity "is the inability to distinguish between the real and the unreal or to be unable to function in reality..." A phenomenon to this is that some - not all - actually think they are the sane ones. There are two reasons for Christian insanity: 1) You're not a true believer in Jesus Christ, or 2) You're out of touch with reality. This is when we lose sight of our spiritual identity and the majesty and the heart of God.