Surah Ghafir Tafseer

ذَلِكُم بِأَنَّهُ إِذَا دُعِيَ اللَّهُ وَحْدَهُ كَفَرْتُمْ وَإِن يُشْرَكْ بِهِ تُوْمِنُوا

(It will be said):"This is because, when Allah Alone was invoked (in worship), you disbelieved; but when partners were joined to Him, you believed!"

meaning, `if you were to go back, this is how you would be.'

This is like the Ayah:

وَلَوْ رُدُّواْ لَعَـدُواْ لِمَا نُهُواْ عَنْهُ وَإِنَّهُمْ لَكَـذِبُونَ

But if they were returned (to the world), they would certainly revert to that when they were forbidden. And indeed they are liars. (6:28)

فَالْحُكْمُ لِلَّهِ الْعَلِيِّ الْكَبِيرِ

So the judgement is only with Allah, the Most High, the Most Great!

means, He is the Judge of His creation, the Just Who is never unjust. He guides whomsoever He wills and sends astray whomsoever He wills; He has mercy on whomsoever He wills and punishes whomsoever He wills; there is no God except Him