Why will we be brought to account for things that are already written for us?

Allaah
has decreed what He has decreed. One of the pillars of faith is to believe
in al-qadaa’ wa’l-qadar
(the Divine will and decree). Allaah has created people and He knows
what they are going to do, because of His vast knowledge. He has given
His slaves freedom of will, and has shown us the right path, so whoever
does good, it is for his own benefit, and whoever does evil, it will
count against him. Allaah says (interpretation of the meaning);

“So
whoever does good equal to the weight of an atom (or a small ant), shall
see it.

And
whoever does evil equal to the weight of an atom (or a small ant), shall
see it.”

[al-Zalzalah
99:7-8]

And
Allaah says (interpretation of the meaning):

“By
Nafs (Adam or a person or a soul), and Him Who perfected him in proportion;

Then
He showed him what is wrong for him and what is right for him.

Indeed
he succeeds who purifies his ownself (i.e. obeys and performs all that
Allâh ordered…).

And
indeed he fails who corrupts his ownself (i.e. disobeys what Allâh has
ordered …).”

[al-Shams
91:7-10]

So
it is not permissible for him to harm anyone unjustly, whether by killing
or in any other way. Whoever does that deserves punishment in this world,
and torment in the Hereafter, for going against the laws decreed by
Allaah.