Why fasting?

The sparrow hawk's swooping contributes to the sparrow's alertness and evolving skills of escape. Although rain, electricity, or fire sometimes harms people, no one curses them. Fasting may be difficult, but it provides the body with energy, activity, and resistance. A child's immune system usually gains strength through illness. Gymnastics are not easy, but they are almost essential to bodily health and strength. People's spirits are refined through worship and meditation as well as through illness, suffering, and hardship. These allow them to acquire Paradise, for God gives a large reward for a little sacrifice. Hardships and sufferings promote people to higher spiritual degrees, and will be returned manifold in the other world. This is why all Messengers experienced the most grievous hardships and sufferings.
Hardship, suffering, and calamity cause believers' sins to be forgiven, warn them away from sins and the seductions of Satan and the carnal self, help them appreciate God's blessings, and open the way to gratitude. Also, they urge the rich and healthy to be concerned about the ill and the poor and to help them. Those who have never suffered cannot understand the condition of those who are hungry, sick, or stricken with a calamity.In addition, these afflictions may help establish closer relations between different social sectors