This day I have perfected your religion for you, completed my favour upon you, and have chosen for you Islam as your religion.. [5:3]
O you who believe! Obey Allâh and obey the Messenger (Muhammad (saws)), and those of you (Muslims) who are in authority. (And) if you differ in anything amongst yourselves, refer it to Allâh and His Messenger (saws), if you believe in Allâh and in the Last Day. That is better and more suitable for final determination. [4:59]