If my action is Pre-decreed by Allaah ( عز و جل), then why should I be punished on committing a sin ?
It is for someone to say: If my action is Pre-decreed by Allaah ( عز و جل), then why should I be punished on committing a sin when it is something already Pre-decreed by Allaah?
The response to this is to say:
You have no proof in using Allaah’s Pre-decree as an excuse for the sin you committed, because Allaah ( عز و جل) did not compel you to commit such sin; and that when you embark on committing it, you do not have the knowledge that it is Pre-ordained upon you, because man does not know of what was Pre-decreed except after it is manifested. So before committing the sin, why did you not take into consideration that Allaah has Pre-decreed obedience on you and therefore you obey Him?
Just as in your worldly affairs you strive to take care of that which you consider good, and you turn away from that which you see as evil, then why do you not treat yourself accordingly in affairs pertaining to the Hereafter?
And I believe that there is nobody after being told that there are two roads that lead to Makkah, one is safe and facilitated and the other is dangerous and difficult, would take the dreadful and difficult road and then say that: “this has been Pre-decreed for me”! He will certainly take the safe and easy road. Consequently, there is no difference if you are told that there is a road to Paradise and another to the Fire. So, if you take the road to the Fire, then you are like the one who took the dreadful and rough road to Makkah. Yourself will criticize this man who took such a road. So, why do you accept for yourself to take the road to the Fire of Hell and turn away from the road to bliss? And if man has a proof in Pre-decree for committing sins, then it would not be removed by sending the Messengers. 
 Since their sinful acts after the sending of the Messengers would still be according to the Pre-decree of Allaah.
Translated by Dr Saleh as Saleh rahimahullaah
Source : Understanding Worship – Fiqh ul-‘Ibadah – Shaykh ibn Uthaymeen