Rabbi Nota Tzvi Frankel . . . taught, "Do only good, for that is why you were created. But who needs to know about it?" In line with this teaching, we should try to do some act of kindness on a routine basis that remains unknown to others. We should let it remain a secret between us, the recipient of our kindness (if it is an act that cannot be done anonymously) and God.

Joseph Telushkin, A Code of Jewish Ethics