The Chazon Ish zt”l is quoted as saying: “The generation that became non-religious came from parents who were religious. These religious parents saw what was happening with their children but, for whatever reason, could not stop them. They cried lonely, bitter tears, they prayed, they fasted, but it was too late to stem the tide. But Hashem does not forget a Jewish tear. If those tears of sincerity did not help to save their own children, they have helped for the grandchildren and, in some cases, great-grandchildren. That’s the reason why these children come back to Yiddishkeit today—because Hashem doesn’t forget Jewish tears.”