Which concept is central to the cycle of samsara?

The concept central to the cycle of samsara is rebirth. Samsara refers to the continuous cycle of birth, death, and rebirth that beings undergo, influenced by their actions (karma). In many Eastern religions, particularly Hinduism and Buddhism, it is understood that the soul or consciousness transitions through various forms of existence based on the moral quality of one's previous actions. This cycle continues until an individual achieves liberation or enlightenment, which signifies the end of this cycle.

Purification is often associated with various spiritual practices aimed at cleansing the self for better karma but is not directly about the process of samsara. Enlightenment represents the ultimate goal of escaping the cycle of samsara, but it is not the process itself. Revelation typically pertains to divine truths being revealed and does not specifically address the cyclical nature of existence that samsara describes. Thus, rebirth is at the core of understanding samsara and its implications in the realm of spirituality and the afterlife.