For the sake of these 36 hidden saints, God preserves the world even if the rest of humanity has degenerated to the level of total barbarism. This is similar to the story of Sodom and Gomorrah in the Hebrew Bible, where God told Abraham that he would spare the city of Sodom if there was a quorum of at least 10 righteous men. Since nobody knows who the Lamedvavniks are, not even themselves, every Jew should act as if he or she might be one of them; i.e., lead a holy and humble life and pray for the sake of fellow human beings.