"The world is built with kindness," King David wrote in Psalm 83. And he should know. He was the great-grandson of Ruth, the Jewish convert who became known as the embodiment of kindness—and whose story we read on the holiday of Shavuos.

Like Ruth before them, the Chassidic masters, as well as the leaders of the Mussar (Ethical) movement, turned performing acts of kindness into a fine art. And in these fifteen stories, renowned figures such as Rav Zusya of Hanipoli, the Gerrer Rebbe, and the Chofetz Chaim show us the way to build a world of kindness for ourselves and our communities.