This novel takes place during World War II, when the Nazis had occupied Holland, and Jews began to be persecuted against and then deported to concentration camps. One of the first hardships they faced was of going into hiding. Just as Anne Frank was hiding in the same country for the same reason, this family took refuge in the house of a non-Jew who was sympathetic and offered to help. To hide for days and weeks at a time, never knowing when you would be discovered was a definite hardship.
Another hardship was that they were eventually discovered, and the family separated and deported. Corrie Ten Boom ended up in a notorious women's concentration camp called Ravensbruck where she endured forced labor, malnutrition, physical and verbal abuse, and illness.