Overall meaning : Just as We sent down revelations to the prophets before you, Muhammad, We have revealed to you this Qur’an in the Arabic language so that people may understand what is in it, in order for you to warn with it the people of the Mother of Cities—Makkah—and those around it from all over the world of a severe chastisement if they do not believe; and to warn mankind of the Day of Judgement, the coming of which is beyond all doubt. One group will, on that day, be in Paradise, the other in the Fire.
Had it been Allah’s will, He would have made all people follow one religion, but He admits whomever He wills of His servants into His mercy; as for those who wrong themselves by reason of their unbelief and evil sins, they will have no guardian to take care of them, nor a helper to protect them against Allah’s punishment.
Rather, these wrongdoers have taken guardians which they worship besides Allah. Allah is the only true guardian who takes charge of all his servants’ affairs! He brings the dead back to life by His power, and He is Able to do all things.