There occurs on page 60 of the book "al-Baraa'ah" - [and you can also see Shaykh Ibn Jibreen's comment upon this saying in this article] - the saying of the Shaykh and Muhaddith, Hammad al-Ansari (rahimahullaah):

The Shaykh - rahimahullaah - was asked about the statement of Sayyid Qutb (see this article for the documentation of this saying from Qutb's book):

And it is necessary for Islaam to judge, since it is a unique, constructive and positivist aqidah which has been moulded and shaped from Christianity and Communism together, [with a] blending in the most perfect of ways and which comprises all of their (i.e Christianity and Communism's) objectives and adds in addition to them harmony, balance and justice.

The words used by Qutb (تصوغ) - forming, shaping, moulding something from something, to forge, fabricate something. And (مزيجا) - compounded, blended, a mixture, medley, blend, combination, compound, alloy - from (مزج) - to mix, mingle, incorporate, blend, i.e. a thing with water, or a thing with something else. And he added to that (كاملا) - complete, perfect. All this from Lane's Lexicon So we have a complete, perfect, mix and blend of each of Communism and Christianity into a medley, compound and alloy, to make up Islam.

Therefore Qutb has stated that Islam is a mixture and blend, a mingling of those ideologies of men that are founded upon atheism and Shirk and shares in their ideals and goals, and that it simply adds the elements of harmony, balance and justice to a combination of those man-made religions and secular systems.

To this, Shaykh Hammaad replied:

If the one who said these words was alive, then his repentance should be sought, so if he repents (then so) otherwise he is to be killed as an apostate. And if he has died then it is obligatory to explain that these words are falsehood. However we do not perform Takfir of him since we have not established the proof against him.

Source: From the book of Shaikh Rabee' "al-Awaasim Mimmaa Fee Kutub Sayyid Qutub Minal-Qawaasim" (p. 24) and who read it out to Shaikh Hammaad himself on the night of 3/1/1415 in order to corroborate it.

Note: Shaykh Salih al-Fawzan said (in his checking and notes upon this book "al-Baraa'ah"), as is indicated in the footnote:

The hujjah (proof) is established upon the one whom the Qur'an and the Sunnah reach. And the disbelief of the Christians is clear in the Qur'an, and more clear than that is the disbelief of the Communists, so how can he mix between kufr and eemaan.

This would indicate that Qutb essentially left the religion through these words of his, and became a kaafir, and it is not known that he recanted and repented from this statement (see corroboration from Shaykh Ibn Jibreen that the one who utters this statements has disbelieved - in this article).

Now, we personally would not call Qutb a kaafir, and still, despite all of his statements (mocking the prophets, accusing the choicest of the Companions with hypocrisy, speaking with the creation of the Qur'an, negating their is a deity above the Throne), we are prepared to make excuses (he may have repented in secret and private before his death from mocking the prophet Moses or saying Islam is a concoction of Communism and Christianity) and give him the excuse of ignorance in some of those issues (the issues in creed, just like we do not make Takfir of the Ash'aris for holding the Qur'an to be created, due to their ignorance and faulty ta'weel). Our thing is to reduce this man's burden and to stop his ignorant deluded fanatical followers from oppressing him and making the situation worse for him. The real problem here is for the Qutbiyyah, the question for them is did Qutb become a kaafir through these words or not? It is they who MUST answer this question, not us, we've already made our stance clear. The problem for the Qutbiyyah is to show their zeal and fervor regarding the criterion between eemaan and kufr and for them to corroborate, practically, whether kufr is through all of beliefs, statements and actions or not (see here, here and here). They need to explain why they continue to aggrandize a man, his books, his doctrines, his methodologies, when according to them, if they are truthful and sincere to what they believe and hold, the man left Islaam and became a kaafir through statement(s) he made, and it is not known (to them) that he recanted or repented from them. And who else is more suitable to corroborate that the statement is one of kufr and its utterer does become a kaafir, other than Shaykh Ibn Jibreen? Comrade, to where is the refuge?