The Bible tells us that Lucifer -- the devil---comes as an "angel of light". Lucifer is another name for the devil. If the devil came to us as ugly and unattractive, no one would want to follow him. If sin, when people originally delve into it, showed itself for the destructiveness and ugliness that it is, people would not participate in it. People get drawn in, deeper and deeper, into what they think is "fun for a season." But it becomes increasingly ugly and destructive.