Authorities who are learned scholars and sages have carefully ascertained that one should atone for the heaviest sins by undergoing a heavy process of atonement and one should atone for lighter sins by undergoing lighter atonement. Chanting the Hare Kṛṣṇa mantra, however, vanquishes all the effects of sinful activities, regardless of whether heavy or light.
Srimad Bhagavata Purana
श्रीमद्भागवतमहापुराणम्
मूल श्लोकः
गुरूणां च लघूनां च गुरूणि च लघूनि च । प्रायश्चित्तानि पापानां ज्ञात्वोक्तानि महर्षिभिः
gurūṇāṃ ca laghūnāṃ ca gurūṇi ca laghūni ca | prāyaścittāni pāpānāṃ jñātvoktāni maharṣibhiḥ
SB 6.2.16