are we cursed or blessed?
Say, “O Allah, Owner of Sovereignty. You grant sovereignty to whom You will, and You strip sovereignty from whom you will. You honour whom you will, and You humiliate whom you will. In Your hand is all goodness. You are Capable of all things.” 3.26.
why there is no justice for injustice and oppression?
If Allah were to hold mankind for their in- justices, He would not leave upon it a single creature, but He postpones them until an appointed time. Then, when their time arrives, they will not delay it by one hour, nor will they advance it. 16.61.