Unfortunately, many Christians seem to have allowed themselves to be sucked into this [self-esteem, self-love, self-actualization] movement under the false impression that the Mosaic command, endorsed by Jesus, that we love our neighbor as ourselves is a command to love ourselves as well as our neighbor. But it really is not. Three arguments may be adduced.
First, and grammatically, Jesus did not say, ‘the first commandment is to love the Lord your God, the second to love your neighbor, and the third to love yourself.’ He spoke only of the first great commandment and of the second which was like it. The addition of ‘as yourself’ supplies a rough and ready, practical guide to neighbor-love, because ‘no one ever hated his own body’ (Eph 5:29). In this respect it is like the Golden Rule to ‘do to others what you would have them do to you’ (Mt 7:12). Most of us do love ourselves. So we know how we would like to be treated, and this will tell us how to treat others. Self-love is a fact to be recognized and a rule to be used, not a virtue to be commanded.
Second, and linguistically, the verb is agapao, and agape love means self-sacrifice in service of others. It cannot therefore be self-directed. The concept of sacrificing ourselves in order to serve ourselves is nonsense.
Third, and theologically, self-love is the biblical understanding of sin. Sin is being curved in on oneself (as Luther puts it). One of the marks of ‘the last days’ is that people will be ‘lovers of self’ instead of ‘lovers of God’ (2 Tim 3:1-5). Their love will be misdirected from God and neighbor to self.