I am at the midway point of the Baha’i nineteen day fast I observe each year. I began in 1971 and will continue, God willing, until 2022. The dates of fasting are March 2-20. The way it works is if you are healthy, between the ages of 15 - 70, not pregnant or breast feeding, then you give up food and water between sunrise and sunset. It is difficult to practice faithfully, but each year about a week before the start I have deep yearning for it. Like no other discipline, it affirms that I am a spiritual being, far beyond the material elements that compose my body. Sometimes I think that if a Divine command were to arrive that I must not ever again pass anything beyond my lips, I would be obedient until death were to release me from the physical bonds entirely. Then like a bird escaping its cage, I would wing my way into grand celestial spheres and sing the ecstasies of heavenly union with Divine Spirit in limitless freedom.
It seems just about every religion has a fasting period. The prophets, who are like Divine Doctors, prescribe it for us for our own good.