TJ Spike: It isn't that he is evil. He has a different view of the world around him. To him, the entire human existence is about "evolving" pushing the race forward for the better of mankind. That process is not a nice process it is a survival of the fittest, and in a modern day society that means...becoming the best you, you can be without limitations.
So Lex views himself as striving to be the perfect man. His hatred of Superman stems from the fact, this alien exists that just was born with all this power. He surpasses Lex Luthor in every way (or so Lex believes) and he or really any man can never be better than him. Add to that this "super" man has a completely opposite philosophy, that man kinds strife to become better man is not about becoming the best YOU at any cost, but at serving and caring for the people and community you love. It is about doing the right thing even when it is difficult, and even when you will lose much to do the right thing.
In Lex Luthor's mind there is no right or wrong, moral or immoral, there is only survival and betterment. It is about how you can manipulate the systems in place, strength your physical and mental self, improve and raise your status in this world, and nothing and no one should stand in mans path to do so.
In this way, Lex Luthor is Superman's exact opposite. Just like in the same way Joker is Batman's exact opposite. Even though, they also share similar ideals.