Our souls are the windows through which the world is filled with light, pores through which it breathes, channels to its supernal source.

There is no function more vital to our universe, nothing more essential to its fulfillment, since for this it was formed.

When we do good, speak words of kindness and teach wisdom, those windows open wide.
When we fail, they cloud over and shut tight.

Such a shame, this loss of light, this lost breath of fresh air! A stain can be washed away, but a moment of life, how can it be returned?

Iggeret HaTeshuva, chapter 1. V’Avraham Zaken, 5738.