CS Lewis

According to Christian teachers, the essential vice, the utmost evil, is Pride. Unchastity, anger, greed, drunkenness, and all that, are mere fleabites in comparison: it was through Pride that the devil became the devil: Pride leads to every other vice: it is the complete anti-God state of mind...

Pride gets no pleasure out of having something, only out of having more of it than the next man. We say that people are proud of being rich, or clever, or good-looking, but they are not. They are proud of being richer, or cleverer, or better-looking than others. If everyone else became equally rich, or clever, or good-looking there would be nothing to be proud about. It is the comparison that makes you proud: the pleasure of being above the rest...

But pride always mean enmity - it is enmity. And not only enmity between man and man, but enmity to God. In God you come up against something which is in every respect immeasurably superior to yourself. Unless you know God as that - and therefore, know yourself as nothing in comparison - you do not know God at all. As long as you are proud you cannot know God. A proud man is always looking down on things and people: and, of course, as long as you are looking down, you cannot see something that is above you.