In Jainism, the belief in afterlife is rooted in the doctrine of karma and the concept of the soul (jīva). According to Jain teachings, every living being possesses an eternal soul that is distinct from the physical body. This soul undergoes countless cycles of birth, death, and rebirth (saṃsāra) due to the accumulation of karma—subtle particles that attach to the soul because of one's actions, thoughts, and intentions.

The assurance of afterlife in Jainism comes from:

1. Scriptural Authority: Jain scriptures such as the Tattvārtha Sūtra, Āgamas, and other texts describe the nature of the soul, karma, and the process of transmigration.
2. Philosophical Reasoning: Jain philosophers argue that the diversity of experiences, abilities, and destinies among living beings can only be explained by the soul’s journey through multiple births and the operation of karma.
3. Testimony of Enlightened Beings: The teachings of the Tīrthaṅkaras (enlightened teachers) and other spiritually advanced souls provide assurance of the soul’s immortality and the reality of afterlife based on their direct realization and knowledge.

Ultimately, assurance of afterlife in Jainism is not just a matter of faith, but is supported by scriptural, logical, and experiential grounds as per Jain philosophy. The ultimate goal is to liberate the soul from this cycle (moksha) by eradicating karma through right faith (samyak darśana), right knowledge (samyak jñāna), and right conduct (samyak chāritra).