What actually happened at Karbala

Allah (swt) is Al-Khabeer which means He knows the innermost of everything; nothing takes place in His domain without His knowledge; no atom moves nor stands still, nor a soul is upset or eased, except that He knows about it. He is the One from Whose knowledge nothing in the earth or in the heavens is hidden; nothing moves in the heavens or in the earth except that He knows about its final resting point or destination.

Allah (swt) has created us with free will. He has given us Aql to distinguish between good and evil. On the day of Judgment we will be rewarded or punished because of our action and choices we made.

Let’s say that every choice we make whether good or evil happens according to Allah's plan. Then why a person should be punished in Aakhira. Does it make sense that the evil things we do in this life were with the will of Allah and for that we will be sent to hell?

No! Allah (swt) the Most Exalted, the Most High is Al Adl.

Adl means moderation; al-`adl is above oppressing or being inequitable to anyone in His decrees and actions. Rather, He grants everyone what is due to him; He puts everything in its right place; nothing ensues from Him except justice.

Allah (swt) has said, "Surely Allah enjoins the doing of justice and of good deeds (to others) and the giving to the kindred, and He forbids indecency, evil, and rebellion; He admonishes you so that you may be mindful" (Qur’an, 16:90).