Verily the most necessary thing is contentment under all circumstances

‎"Verily the most necessary thing is contentment under all circumstances; by this one is preserved from morbid conditions and from lassitude. Yield not to grief and sorrow: they cause the greatest misery. Jealousy consumeth the body and anger doth burn the liver: avoid these two as you would a lion." - Baha'u'llah: Health and Healing, Page: 460