The Talmud...

"Once, as Rabbi Yohanan ben Zakkai was coming forth from Jerusalem, Rabbi Joshua followed after him and beheld the Temple in ruins. 'Woe unto us,' Rabbi Joshua cried, 'that this, the place where the iniquities of Israel were atoned for, is laid waste!'

"'My son,' Rabbi Yohanan said to him, 'be not grieved. We have another atonement as effective as this. And what is it? It is acts of loving-kindness, kindness, as it is said, For I desire mercy and not sacrifice [Hosea 6.6].
"

Talmud, Abot de Rabbi Nathan 6