Rasoolullah :saws: said, “Indeed, what I fear for my Ummah are misguided leaders, and that when the sword is drown out against them, it will not be lifted from them until the Day of Judgement. And the Hour will not come, until sections of my Ummah will follow the mushrikeen (those who worship others along with Allaah), and until many sections of my Ummah will worship idols. And there will be in my Ummah thirty liars; all of whom will claim that he is a Prophet. But I am the last and the seal of the Prophets; there is no Prophet after me. And there will not cease to be a group from my Ummah being helped upon the truth, not being harmed by those who oppose them; until the command of Allaah comes.”
(Saheeh: Related by Aboo Daawood (no. 3952), from Thawbaan (radiyallaahu ’anhu) It was authenticated by al-Haafidh Ibn Hajar in al-Mataalibul-’Aaliyah (4/264))
Books and divine revelations are revealed by Allah to Prophets. No new prophet after him :saws: therefore equals no new revelation, thus the Qur'an is the final revelation from Allah.