In a single moment of sincere repentance, a person can rectify the sins of an entire lifetime.

They said about Rabbi Elazar ben Durdaya that he did not leave a single prostitute in the world with whom he did not engage in intimate relations. Once he heard that there was a prostitute in one of the cities overseas who would take a purse full of dinars as her payment. He took a purse of dinars and went and crossed seven rivers to reach her.

When they were engaged in the customary matters [a euphemism for intercourse], she passed wind and said: Just as this passed wind will not return to its place, so too, Elazar ben Durdaya, they will not accept him in repentance.

Elazar ben Durdaya went and sat between two mountains and hills, he said: Mountains and hills, pray for mercy on my behalf. They said to him: Before we pray for mercy on your behalf, we must pray for mercy on our behalf…He said: Sun and moon, pray for mercy on my behalf. They said to him: Before we pray for mercy on your behalf, we must pray for mercy on our behalf…He said: Stars and constellations, pray for mercy on my behalf. They said to him: Before we pray for mercy on your behalf, we must pray for mercy on our behalf….

Elazar ben Durdaya said: Clearly the matter of repentance is dependent only on me. He placed his head between his knees and wept bitterly until his soul departed his body. A divine voice emerged and said: Rabbi Elazar ben Durdaya is destined for life in the World to Come.

When Rabbi Yehuda HaNasi heard this, he wept, and said: There is a person who acquires his share in the World to Come only after many years of toil, and there is one who acquires his share in the World to Come in a single moment. And Rabbi Yehuda HaNasi said: It is not sufficient that they accept the penitents, but they even call them: Rabbi.

A single moment of repentance and good deeds in this world is preferable to all the life in the World to Come. (Avoda Zara 17a; Mishna Avot 4:17)