Those who do not believe in Allah and Prophet Muhammad (peace be upon him) the way true Muslims do, have no possibility of a genuine success. They will continue to bear the burden of miseries and will burn with the same in the life hereafter.
This prophecy if for those living in Arabia who were hostile to Islam. They are given only one option and that is to begin believing like Muslims. Because Hijaz had to be made the center of Quranic revolutions, that was why no traces of traditionalism were allowed to stay. Muslims still consider anti-Islam activity in Makkah and Madina a huge crime.
Angels may govern heaven, yet the earth has to be governed by men of faith who believe in the Almighty and implement His rules here.
This revolution existed in its finest shape and rules of Allah implemented here up until the martyrdom of Hazrat Usman (R.A). There was the law of Quran and there was a team based upon its practicality. The team did not consider itself to be the creator of law, rather it considered itself to be a subordinate of Allah Almighty and obeyed and made others obey His laws and orders. The prophet (peace be upon him) being Allah’s follower, made his companions subordinates of Allah, who were with him in implementing the superiority and respect of the law of Allah.
(He may forgive whoever He wants and may burn whoever He wants)
He who intends to implement this law, and gradually begins to do it efficiently, will get his sins forgiven. He who ebbs away gradually from this law will face penalization.
(And Allah is the merciful, the beneficent)
The system which the Almighty got established with the help of his true disciples seeks to forgive sins of every righteous person and bring forth a programme for the betterment of humanity at large.