In The Name of Allaah, The Most Merciful, The Bestower of Mercy

It has been reported in an authentic hadeeth -[in Saheeh Al Bukhaari and Saheeh Muslim]- that: “A man will be brought on the Day of Resurrection and thrown into the Fire, then his intestines will spill forth in the Fire and he will go around it as a donkey goes around a millstone. The people of Hell will gather around him and will say: O So and so! What is the matter with you; did you not use to enjoin good and forbid evil? He will say: Yes, I used to enjoin good, but did not do it; and I used to forbid evil and did it [i.e. commit the evil I used to forbid. [Al-Bukhaari 3267 & Muslim 2989]

After quoting this Hadeeth, Shaikh Rabee Bin Haadi [hafidhahullaah] said: Indeed, there maybe someone who is worse than this man, for he [i.e. the one worse than the man mentioned in this Hadeeth] enjoins evil and forbids good, so what will be his state of affairs, and Allaah’s Refuge is sought?! Therefore, seeking knowledge should be for the sake of Allaah and also to act [upon it], otherwise knowledge will be a cause of evil upon [the seeker] and thus he’ll remain in two situations- either in a situation where one is afflicted with the disease of ignorance or in a state where one is not benefited by knowledge, rather it becomes harmful knowledge. The knowledge Muhammad [sallal laahu alayhi wasallam] brought is beneficial in and of itself, but if a person does not act [i.e. after acquiring it], it will be a cause of evil and harm for him and he might [also] harm others. Allaah [The Exalted] said:

وَقُلِ اعْمَلُوا فَسَيَرَى اللَّهُ عَمَلَكُمْ وَرَسُولُهُ وَالْمُؤْمِنُونَ ۖ وَسَتُرَدُّونَ إِلَىٰ عَالِمِ الْغَيْبِ وَالشَّهَادَةِ فَيُنَبِّئُكُم بِمَا كُنتُمْ تَعْمَلُونَ

And say [O Muhammad] “Do deeds! Allaah will see your deeds, and [so will] His Messenger and the believers. And you will be brought back to the All-Knower of the unseen and the seen. Then He will inform you of what you used to do. [Surah At-tawbah. Aayah 105]

Act based on knowledge and know Allaah by His Perfect Names and Attributes -from Allaah’s Book [i.e. the Qur’aan] and the [authentic] Sunnah of His Messenger [sallal laahu alayhi wasallam]. Worship Allaah based on that which the Messenger conveyed [i.e. the authentic Sunnah] and based on the texts of the Qur’aan. Neither worship Allaah based on ignorance nor desires, rather worship Allaah based on knowledge. That which is sought after from seeking knowledge is to act upon it, and acting cannot be [fulfilled] except after acquiring knowledge, just as Allaah [The Blessed and Exalted] said:

فَاعْلَمْ أَنَّهُ لَا إِلَٰهَ إِلَّا اللَّهُ وَاسْتَغْفِرْ لِذَنبِكَ وَلِلْمُؤْمِنِينَ وَالْمُؤْمِنَاتِ ۗ

So know [O Muhammad] that Laa ilaaha ill-Allah [none has the right to be worshipped but Allaah], and ask forgiveness for your sin, and also for [the sin of] believing men and believing women. [Surah Muhammad. Aayah 19]

Imaam Al-Bukhaari wrote a chapter based on this Aayah, saying: Chapter: “Knowledge precedes speech and action”,  because it is obligated on us to act based on knowledge and we are only to worship Allaah based on knowledge. We do not worship Allaah based on ignorance or desires.

Marhaban Yaa Taalibal Ilm. Pages 270-271. Slightly paraphrased