Is it true that Al-Ghazali's book "Ihya' 'Ulum al-Din" contains errors, and what are the reliable jurisprudential books free from errors?

Scholarly opinions regarding Imam Al-Ghazali and his book "Ihya' 'Ulum al-Din" have varied; some have praised him to the point of exaggeration, while others have censured him. Some have also pointed to his disquietude and frequent shifts in states.

As for the book "Ihya' 'Ulum al-Din," it contains much benefit, but it also includes "calamities and misfortunes" and corrupt material from the words of philosophers, weak and fabricated hadiths, and Sufi fallacies.

Some scholars, such as Imam al-Tartushi, warned against it, saying that Al-Ghazali "filled his book with lies about the Messenger of Allah, peace and blessings be upon him," and the doctrines of philosophers, and he advised burning it.

Similarly, Imam al-Mazari, Qadi 'Iyad, Ibn al-Jawzi, Ibn Taymiyyah, and Al-Dhahabi criticized "al-Ihya'" for similar reasons, emphasizing the presence of invalid hadiths within it and passages that contradict the the Sunnah, and its reliance on statements that are unacceptable to reason or Islamic law.

In conclusion, it is recommended to rely on books of creed based on the methodology of the Salaf, and books of fiqh from the accredited schools of thought.