To show submission to Allah’s commandments.
To attain Taqwah (dutifulness to Allah, which drives us to obey Allah and holds us from disobeying Him.)
Allah the Exalted said: (O you who have believed, decreed upon you is fasting as it was decreed upon those before you that you may become righteous)
To sense Allah’s favors upon us. Especially when we refrain from what’s lawful, we appreciate having it and sense the sorrow of losing it.
To discipline oneself by opposing desire, lust, and Satan.
To feel for the poor and needy and appreciate Allah’s favors to us.
Additionally, there are many proven health benefits of fasting.