Overall meaning : Allah has promised those of you who believe and do righteous deeds to grant them power in the land as He granted it to the believers before them, to establish for them their religion which He has chosen for them—namely Islam—by making it prevail over all other religions, and to change their state of fear into a state of reassurance and security, provided that they sincerely worship Me and associate with Me no partners whatsoever. Only the disobedient wicked would, after such bestowal of My grace upon them, show ingratitude.
Duly attend to your prayers, duly pay zakat due on your wealth and obey the Messenger in order to attain Allah’s mercy.
Never think, Prophet, that the unbelievers will ever frustrate Allah’s plan and purpose. He has power over all of them. Their abode in the hereafter will be Hell. What an evil destination!