what are some ways that wiesel and other jews at the camps try to observe their religon?

Ellie and his fellow Jews, at least initially, attempt to observe their faith in secrecy, "Evenings, as we lay on our cots, we sometimes tried to sing a few Hasidic melodies. Akiba Drumer would break out hearts with his deep grave, voice." Even though the prisoners are starving they choose to fast to observe Yom Kippur. Ellie's faith, however, begins to change. Elie can't reconcile with his God letting this happen. He chooses not to fast as a symbol of his increasing disillusionment with his faith.