Upvote:0
Morally, kamma is cancelled by learning evil deeds are evil deeds and thus no longer having any inclination to perform evil deeds and only inclination to perform good deeds, as follows:
But because you see your transgression as such and make amends in accordance with the Dhamma, we accept your confession. For it is a cause of growth in the Dhamma & Discipline of the noble ones when, seeing a transgression as such, one makes amends in accordance with the Dhamma and exercises restraint in the future.
DN 2
172. He who having been heedless is heedless no more, illuminates this world like the moon freed from clouds.
173. He, who by good deeds covers the evil he has done, illuminates this world like the moon freed from clouds.
Ultimately, kamma is cancelled by the realisation of not-self (anatta); that the doer of kamma was not a self but was ignorance, as follows:
"Master Gotama, is stress self-made?"
"Don't say that, Kassapa."
"Then is it other-made?"
"Don't say that, Kassapa."
"Then is it both self-made and other-made?"
"Don't say that, Kassapa.
SN 12.17
And what is the cessation of kamma? From the cessation of contact is the cessation of kamma; and just this noble eightfold path — right view, right resolve, right speech, right action, right livelihood, right effort, right mindfulness, right concentration — is the path of practice leading to the cessation of kamma
Upvote:3
Bad kamma once sown cannot be erased completely, but by cultivating Sila, Samadhi, Panna, the suttas say it's possible to lessen the intensity/severity of it. See the case of Ven. Angulimala in MN 86 and the Buddha's famous quote:
Bear with it, brahman! Bear with it! The fruit of the kamma that would have burned you in hell for many years, many hundreds of years, many thousands of years, you are now experiencing in the here-&-now.
Also see the Lonaphala Sutta - AN 3.99