The act of setting oneself on fire

Amberist: a religious factor brought upon oneself by setting your standards to the lowest of low and being in a relationship with anyone

There may be a word that is based in religious terminology. I would refer to this as self-immolation.

Set oneself on fire

Self-immolation refers to the act of intentionally setting oneself on fire as a form of protest or sacrifice. It is a drastic and often fatal form of demonstration that has been used to draw attention to various political or social causes.