Verily, We shall remove the torment for a while. Verily, you will revert.
means, `if We were to remove the torment from you for a while, and send you back to the world, you would go back to your former state of disbelief and denial.'
This is like the Ayat:
وَلَوْ رَحِمْنَـهُمْ وَكَشَفْنَا مَا بِهِمْ مِّن ضُرٍّ لَّلَجُّواْ فِى طُغْيَـنِهِمْ يَعْمَهُونَ
And though We had mercy on them and removed the distress which is on them, still they would obstinately persist in their transgression, wandering blindly. (23:75)
وَلَوْ رُدُّواْ لَعَـدُواْ لِمَا نُهُواْ عَنْهُ وَإِنَّهُمْ لَكَـذِبُونَ
But if they were returned (to the world), they would certainly revert to that which they were forbidden. And indeed they are liars! (6:28)
The Meaning of the "Great Batshah"
يَوْمَ نَبْطِشُ الْبَطْشَةَ الْكُبْرَى إِنَّا مُنتَقِمُونَ