Question:
This person asks about the one who says: "I only believe in the Qur'an, as for the Sunnah, then it is not truthful."
Shaykh Saalih al-Fawzaan:
This is a disbeliever. This is a disbeliever.
For he is a liar, he does not take the Qur'an as being truthful. The Qur'an commands the following of the Sunnah. Allah, the Almighty, says:
"And whatsoever the Messenger gives you, take it, and whatsoever he forbids you, abstain (from it)." (al-Hashr 59:7)
The Qur'an has commanded us to follow the Sunnah of the Messenger, sallAllahu 'alayhi wa sallam. So the one who says: "I believe in the Qur'an but I do not believe in the Sunnah." He has (in reality) disbelieved in the Qur'an and the Sunnah, for he has taken the Qur'an not as being truthful.
Allah says in the Qur'an:
"And whatsoever the Messenger gives you, take it, and whatsoever he forbids you, abstain (from it)." (al-Hashr 59:7)
And Allah, the Allmighty, says:
"And if you obey him..." Who is "him" (in this verse)? The Messenger.
"If you obey him, you shall be on the right guidance. The Messenger's duty is only to convey (the message) in a clear way (i.e. to preach in a plain way)." (al-Noor 24:54)
The Exalted said:
"Obey Allah and obey his messenger" (an-Nisaa 4:59)
The Exalted says:
"He who obeys the Messenger, has indeed obeyed Allah" (an-Nisaa 4:80)
So those who do not regard the Sunnah as being truthful, he is a disbeliever. He is a disbeliever, even with regards to the Qur'an.