Is fasting obligatory?

Certainly, I will answer your question in light of the Quran and Sunnah, in accordance with the Hanafi school of thought. Fasting is one of the five pillars of Islam and a obligatory act of worship. Therefore, fasting is obligatory for every Muslim who has no valid excuse. The Holy Quran states: "O you who have believed, it has been decreed upon you all as it had been decreed upon those before you that you may become righteous." (Surah Al-Baqarah, Verse 183) The Messenger of Allah (peace and blessings be upon him) also declared the obligation of fasting in many of his noble hadiths. For example, in the famous hadith where Jibril (peace be upon him) asked about the pillars of Islam, fasting was also mentioned as obligatory. Therefore, it is incumbent upon every Muslim who is sane, has reached puberty, and is able to fast, to fast during the month of Ramadan. However, there are also dispensations for those who have valid excuses such as illness, travel, pregnancy, or breastfeeding, such as postponing the fast or giving fidya (ransom). There are detailed rulings in the Hanafi school of thought for these situations.