At the end of Tolstoy's short story "What Men Live By," Michael reveals himself to Simon as an angel, clothed in bright light. He tells Simon that, during his time on earth, he has learned that men live by love for others, not selfishness.
People do not know what others need, or even what they themselves need, since no one even knows whether they will still be alive by the end of the day. When Michael was a man, he was saved by the love and pity of a stranger, and this salvation through charity is a universal principle of humanity, sanctioned by God.
God does not make men independent and self-sufficient, because he wants them to live together and help one another. Therefore, while people spend much of their time looking after their own interests and consider that this is the best way to survive, in fact, they live by their love for others. Michael concludes with the message,
He who has love, is in God, and God is in him, for God is love.
Tolstoy is always a didactic writer, particularly in his short stories, but here, he is able to use Michael's voice to convey the moral of the story to the reader in precisely the same words that Simon receives it. This means that the story has even more of the quality of a parable than is usually the case with Tolstoy.