Vanity of vanities, saith the Preacher, vanity of vanities; all is vanity.
In many religions vanity, in its modern sense, is considered a form of self-idolatry, in which one rejects God for the sake of one's own image, and thereby becomes divorced from the graces of God. The stories of Lucifer, Narcissus (who gave us the term narcissism) and others attend to a pernicious aspect of vanity. Philosophically speaking, vanity may refer to a broader sense of egoism and pride. Friedrich Nietzsche wrote that "vanity is the fear of appearing original: it is thus a lack of pride, but not necessarily a lack of originality." One of Mason Cooley's aphorisms is "Vanity well fed is benevolent. Vanity hungry is spiteful."
In Christian teachings vanity is considered an example of pride, one of the seven deadly sins. This list evolved from an earlier list of eight sins, which included vainglory as a sin independent of pride.
In Orthodox church, vanity is one of eight sinful and diabolical passions, the fight against which is a major task of every Orthodox Christian.