Shaykh Muhammad bin Saleh al-‘Uthaymeen, may Allah have mercy upon him, gives a brilliant lecture on the topic of sticking to the Prophetic Sunnah.
A small excerpt from the book:
“The effects of sticking to the Sunnah” is the subject matter of this lecture. The Sunnah and the Qurʾān are interdependent; the Sunnah is considered an authority over the human being and, therefore, they are as obliged to comply with it as they are with the Qur’ān.
Definition of the Sunnah: it is the established sayings, practices/actions and tacit approvals of the Prophet (Peace be upon him); it is obligatory to practice it as the Qurʾān. However, using the Qur’ān to prove something requires considering one aspect while using the Sunnah requires considering another aspect.
Concerning the Qurʾān; There should be a match between the implication of the text used for proof and the ruling for which such text is used to prove: and there is no doubt that scholars in this regard due to the relative difference in their respective knowledge and understanding skills.
Scholars have different opinions about the signification of the Noble Qurʾān depending on their knowledge, understanding, how firm their belief in Allāh (The All-Mighty and Sublime) is and as for glorification of His sacred matters.