The Spirits' Book
Book Three - Moral Laws
Chapter V - IV. Law of Preservation
Voluntary Deprivations – Mortifications
727. Since we should not create voluntary suffering for ourselves that serves no purpose for others, should we protect ourselves from that which we can anticipate or that which threatens us?
“The instinct of self-preservation has been given to all beings to serve as a safeguard against danger and suffering. Chastise your spirit and not your body, mortify your pride, and stifle the selfishness that like a snake devours your heart. By doing this, you will do more for your development than any amount of mortifications, which are no longer appropriate for the time period in which you are living.