In Jainism, merit is called punya. Punya is the positive karmic result you accumulate through pure, Spiritual actions and right conduct, while papa is the negative karma you shed or accumulate through harmful deeds.

Biggest merit (highest punya) in Jain thought

• The most important and earning-merit action is living a life of complete non-violence (ahimsa) combined with truthfulness (satya), non-stealing (asteya), celibacy (brahmacharya), and non-attachment (aparigraha) — i.e., the Mahavratas that Jain monks and nuns follow. For lay practitioners, these vows guide daily conduct and generate the greatest punya over time.
• Beyond these vows, sustained spiritual practices that purify the mind and remove karmic influx are highly meritorious: right faith (samyak darshan), right knowledge (samyak jnana), and right conduct (samyak charitra) together (the three jewels) lead toward the destruction of karmas and ultimate liberation.
• Renunciation, self-discipline, deep compassion (ahiṃsā) toward all beings, and disciplined austerities (tapas) when practiced with right intention also yield very strong punya.
• The ultimate aim of punya in Jainism is moksha (liberation from all karmic bondage). The single most meritorious course, then, is to reduce and eventually shed karmas that bind the soul, by living in alignment with Jain ethics and spiritual practice.

Note on Digambar vs. Shwetambar

• Both traditions affirm ahimsa, truth, non-stealing, celibacy, and aparigraha as foundational, and both emphasize samyak darshan, samyak jnana, and samyak charitra as essential for true punya and spiritual progress. Minor emphasis or phrasing may vary in scriptures, but the core idea of highest merit being aligned with pure conduct and liberation remains consistent.

If you’d like, I can point you to a concise Jain Knowledge resource that discusses punya, karma, and liberation in more detail. You can read more here