Surah 43. Az-Zukhruf, Ayah 76

The wrong-doers suffer not because Allah is unjust or cruel, nor as a deterrent to others, for the probationary period will then have passed, but because their evil deeds must bear their inevitable fruit. Allah's Grace was ever ready to offer opportunities for Repentance and Forgiveness. But they rejected them. They were unjust to themselves. This is complementary to the doctrine of works and their fruits, as explained in n. 4671 above.