Final answer:
Fasting is included as a part of worship in Judaism, Christianity, and Islam.
Step-by-step explanation:
The belief that is shared by Jews, Christians, and Muslims is a) Fasting is included as a part of worship. Fasting is practiced in all three religions as a way of expressing devotion to God and seeking purification of the soul. For example, Jews fast on Yom Kippur, Christians observe Lent, and Muslims fast during the month of Ramadan.