I don't understand what doing the sunnah has to do with loving Prophet Muhammad (peace be upon him). After all, we do our deeds for Allah's sake and not for Prophet Muhammad's sake (peace be upon him). From my understanding of Islam, a classic example of not loving the Prophet Muhammad (peace be upon him) is not following the Sunnah. However, it seems to contradict doing things for Allah's sake and this is confusing me. I just don't understand why I can't love the Prophet (peace be upon him) without doing the sunnah (if that's true).
The commands mentioned in the Qur’aan and Sunnah to follow the laws of Allaah and His Messenger, and the prohibitions on introducing innovations into the religion are quite clear. Allaah says (interpretation of the meaning):
“Say (O Muhammad to mankind): ‘If you (really) love Allaah, then follow me (i.e. accept Islamic Monotheism, follow the Qur’aan and the Sunnah), Allaah will love you and forgive you your sins’”
[Aal ‘Imraan 3:31]
“Follow what has been sent down unto you from your Lord (the Qur’aan and Prophet Muhammad’s Sunnah), and follow not any Awliyaa’ (protectors and helpers who order you to associate partners in worship with Allaah), besides Him (Allaah). Little do you remember!”
“And verily, this is My straight path, so follow it, and follow not (other) paths, for they will separate you away from His path”
And the Prophet (peace and blessings of Allaah be upon him) said: “The most truthful of speech is the Book of Allaah and the best of guidance is the guidance of Muhammad, and the most evil of things are those which are newly-invented.”