We do not understand the Shoah, and many other sufferings of the Galut. But in the near future, we will start to grasp this, as יְהִי אוֹר, "there will be light," and in that light we will be able to comprehend.
"Towards evening time there will be light (Zecharyah 14:7)," in Acharit HaYamim, at the time that the Geula comes close. With that: "The people that walked in darkness have seen a great light (Yeshayah 9:1)." (Ramchal, Tikkunim Chadashim, Tikkun 39)
