How does the Culdian concept of Good and Evil differ from that of Christians?

It does not differ from concepts held by better informed, more enlightened Christians who have studied the matter in depth. However, it differs considerably from the beliefs of those who equate Evil with a whole range of so-called sins and the breach of priestly prohibitions. This is known as the ‘simplex concept’. Evil is much more subtle. The simple view that Evil results from succumbing to ‘temptation’ is quite inadequate for understanding the subtle nature of Evil as it manifests today. Those who would have no difficulty in recognizing such temptations, or in rejecting them, all too easily fall for the more sinister form of Evil masquerading as Good.