"Say (O! Muhammad [صلى الله عليه وسلم] to mankind): 'If you (really) love ALLAH, then follow me (i.e. accept Islamic Monotheism, and follow the Qur'an and Sunnah), ALLAH will love you and forgive you your sins. And ALLAH is Most Forgiving, Most Merciful.'" (Al-Qur'an; Surah Aal 'Imran; Ayat 31)
"And whatsoever the Messenger (Muhammad [صلى الله عليه وسلم]) gives you, take it, and whatever he forbids you, abstain (from it)." (Al-Qur'an; Surah Al-Hashr; Ayat 7)
"Nor does he (Muhammad [صلى الله عليه وسلم]) speak of his own desire. It is only an inspiration that is inspired. He (Muhammad [صلى الله عليه وسلم]) has been taught (this Qur'an) by one mighty in power (Jibril)." (Al-Qur'an; Surah An-Najm; Ayat 3-5)
"Say (O! Muhammad [صلى الله عليه وسلم]: 'Obey ALLAH and obey the Messenger (Muhammad [صلى الله عليه وسلم].' But if you turn away, then ALLAH loves not the disbelievers." (Al-Qur'an; Surah Aal 'Imran; Ayat 32)
"O! You who believe! Obey ALLAH and obey the Messenger (Muhammad [صلى الله عليه وسلم]) and those among you who are in authority. And if you differ in anything among yourselves, then refer it to ALLAH and His Messenger (Muhammad [صلى الله عليه وسلم]), if you believe in ALLAH and the Last Day. That is better and more suitable for final determination." (Al-Qur'an; Surah An-Nisa'; Ayat 59)
"He who obeys the Messenger (Muhammad [صلى الله عليه وسلم] has indeed obeyed ALLAH, but he who turns away, then We have not sent you (O! Muhammad [صلى الله عليه وسلم]) as a watcher over them." (Al-Qur'an; Surah An-Nisa'; Ayat 80)