Love for oneself is intending well to oneself alone, not to others except for the sake of oneself—not the church, the country, or any human community. It is helping them solely for the sake of one’s own reputation and rank and glory. Unless these can be seen in the services we offer, we are saying at heart, “What difference does it make? Why should I? What’s in it for me?” So we forget it. We can see from this that people who are absorbed in a love for themselves do not love their church or country or community or any constructive activity. They love only themselves. Their only pleasure lies in self-gratification; and since the pleasure that stems from love constitutes human life, their life is a life of self. A life of self is a life that depends on what we claim as our own, and in its own right what we claim as our own is nothing but evil.
People who love themselves do love their own as well, their own being specifically their children and grandchildren and more broadly all who ally with them, whom they call “their own people.” Loving both the former and the latter is actually loving themselves, because they regard the others as though they were in themselves, and focus on themselves in others. These “others” who are claimed as their own include everyone who praises and reveres and worships them.
We can gather what love for oneself is like by comparing it to heavenly love. Heavenly love is loving constructive activity for its own sake, or loving for their own sake the worthwhile things we do for our church, our country, the human community, and our fellow citizens. This is really loving God and loving our neighbor, since all constructive activities and all worthwhile actions come from God and are the neighbor whom we are to love. In contrast, people who love these activities for the sake of self love them only as slaves who wait on them. It follows that people devoted to a love for themselves want their church, their country, the human community, and their fellow citizens to be their servants rather than wanting to serve them. They station themselves above these neighbors and put them down. So to the extent that people are devoted to a love for themselves, they move themselves away from heaven because they move themselves away from heavenly love.
from Heaven and Hell, Sections 556-557