In Every religion, fasting is very important, I'll take some close definitions and importance of fasting in some of them. (Personally I like how Baha’i’s view the fast as well as Buddhist's wink
In Islam,
According to the Quran, every Muslim (who can) must fast in the month of Ramadan 2:183-185. And fasting has to be done collectively at the community level. Unlike a Buddhist monk or a Hindu saint, a Muslim does not have to go to a mountain or a forest retreat to develop their spirituality through fasting and prayer. Moreover, it is not necessary for this type of retreat-based, solitary spiritual development to be done in Ramadan. That can be done in any month. This shows that a Muslim cannot advocate a spirituality that is based on individual and subjective experience. Therefore, in Islam, individual and subjective spiritual development is not the purpose of fasting in the month of Ramadan.
Since the Quran prescribed fasting specifically in the month of Ramadan, it is important to know the significance of this special time. A special feature of the Quran is that whenever it gives a command for action, it also provides the wisdom behind it. It tells what the final result of that action will be in this world, if it is successfully carried out. In this way the Quran provides a pragmatic test for people to see whether or not they are moving toward that desired result. Regarding fasting, the Quran says:
O ye who believe! Fasting is prescribed to you as it was prescribed to those before you, that ye may (learn) self-restraint . [al-Baqarah 2:183] Translation: Yusuf Ali
In the above verses, three results of fasting in Ramadan have been mentioned:
1) Taqwaa : learning self-restraint
2) Takbir : glorifying Allah Almighty because of being guided
3) Shukra : being grateful .
In Christian Faith
Although, Jesus fasted for 40 days and nights in the wilderness and Moses fasted twice on the mountain for 40 days and 40 nights with neither food nor water.
Now days, there is not a specific period or duration for the fast, and this latter can last 3 days or a month depending on the desire of the believer or the pastor…
In the Baha’i Faith,
The fasting period, which lasts nineteen days starting as a rule from the second of March every year and ending on the twentieth of the same month, involves complete abstention from food and drink from sunrise till sunset. It is essentially a period of meditation and prayer, of spiritual recuperation, during which the believer must strive to make the necessary readjustments in his/her inner life, and to refresh and reinvigorate the spiritual forces latent in his soul. Its significance and purpose are, therefore, fundamentally spiritual in character. Fasting is symbolic, and a reminder of abstinence from selfish and carnal desires."
Fasting is the cause of awakening man. The heart becomes tender and the spirituality of man increases. This is produced by the fact that man's thoughts will be confined to the commemoration of God, and through this awakening and stimulation surely ideal advancements follow... Fasting is of two kinds, material and spiritual. The material fasting is abstaining from food or drink, that is, from the appetites of the body. But spiritual, ideal fasting is this, that man abstain from selfish passions, from negligence and from satanic animal traits. Therefore, material fasting is a token of the spiritual fasting. That is: `O God! As I am fasting from the appetites of the body and not occupied with eating and drinking, even so purify and make holy my heart and my life from aught else save Thy Love, and protect and preserve my soul from self-passions... Thus may the spirit associate with the Fragrances of Holiness and fast from everything else save Thy mention.
So according to the Bahá’í Faith, the purpose of fasting is to bring us closer to God. `Abdu'l-Bahá explains:
Fasting is a symbol. Fasting signifies abstinence from lust. Physical fasting is a symbol of that abstinence, and is a reminder; that is, just as a person abstains from physical appetites, he is to abstain from self-appetites and self-desires. But mere abstention from food has no effect on the spirit. It is only a symbol, a reminder. Otherwise it is of no importance. Fasting for this purpose does not mean entire abstinence from food. The golden rule as to food is, do not take too much or too little. Moderation is necessary. There is a sect in India who practice extreme abstinence, and gradually reduces their food until they exist on almost nothing. But their intelligence suffers. A man is not fit to do service for God with brain or body if he is weakened by lack of food. He cannot see clearly.
Amazingly, Abdu'l-Bahá talks about moderation while fasting, I find this very interesting because of the following:
Although, in Buddhism, Fasting is recognized as one of the methods for practicing self-control. The Buddha advised monks not to take solid food after noon.
A Buddhist monastic community is prone to fasting as an ascetic practice or dhutanga. Dhutangas are a list of 13 practices, four of which pertain to food eaten once a day, eaten at one sitting, reducing the amount you eat, and eating only the food that you receive at the first seven houses. These practices are voluntary in a Buddhist monastic’s life.
The Buddha’s spiritual awakening is closely linked to fasting. The moment he stopped fasting, he realized his great awakening.
The story of the Buddha is in itself a lesson in fasting, as he was a prince who renounced all worldly desires in search of the truth about life. He found teachers to tell him what they thought about life, and drew on his experiences with people in times of old age, death and rebirth. His experiences made him realize that desire was the root of all evil and of human life. Food was man’s first and most basic desire. So, he decided to give up this desire and gain freedom from the tangles of worldly life and suffering. Initially, he at only one grain of rice and a sesame seed per day. He soon grew so thin that he could touch his spine by pressing his stomach. He lost all strength to meditate and realized that he would die before he learnt the great lessons of this world. He had to understand his mind. He also saw that he could no longer control his desire by force.
At that time, a young maiden offered him a bowl of porridge which he accepted. The food gave him the strength he needed to meditate and he realized Buddhahood. His experiment to quit fasting taught him to lead life in moderation. Moderation soon became the central tenet of Buddhist practice.
Some of these ideas can also be found in the writings of Gandhi: A genuine fast cleanses the body, mind and soul. It crucifies the flesh and to that extent sets the soul free. A sincere prayer can work wonders. It is an intense longing of the soul for its even greater purity. Purity thus gained, when it is utilized for a noble purpose, becomes prayer.
I believe that there is no prayer without fasting, and there is no real fast without prayer.
I know that the mental attitude is everything. Just as prayer may be merely a mechanical intonation as of a bird, so may a fast be a mere mechanical torture of the flesh... Neither will touch the soul.
Also, when you fast, it’s not important to tell the whole world that you are fasting, in some instances you may but it’s not important. Btw, rather let your friends know before you fast. Jesus says in Matthew 6:17-18 "But when you fast, put oil on your head and wash your face, so that it will not be obvious to men that you are fasting, but only to your Father, who is unseen; and your Father, who sees what is done in secret, will reward you."
Ah one more thing, it’s not to scare you but, when you fast, temptation will walk side by side with you also. Those in the Christian faith may say that Jesus was alone when he fasted for 40 days and nights in the wilderness. Well, he was not exactly alone, the devil was with him. (Luke 4:2).
Good Luck ! grin