Ibn Taymiyyah said:

حكي أن أبا حامد الغزالي بلغه أن من أخلص لله أربعين يوما تفجرت ينابيع الحكمة من قلبه على لسانه

قال: فأخلصت أربعين يوما فلم يتفجر شيء فذكرت ذلك لبعض العارفين فقال لي: إنك إنما أخلصت للحكمة ولم تخلص لله تعالى

”… News reached Abu Hamid al-Ghazali that whoever proves sincere to Allah for forty days, wisdom springs from his heart and is established upon his tongue.

He (al-Ghazali) said, ‘So I became sincere to Allah for forty days but nothing happened so I mentioned this to a righteous person and he said to me, ‘You were not sincere for the sake of Allah, rather you were sincere for the sake of attaining wisdom.”

Ibn Taymiyyah then says:

وذلك لأن الإنسان قد يكون مقصوده نيل العلم والحكمة أو نيل المكاشفات والتأثيرات أو نيل تعظيم الناس له ومدحهم إياه أو غير ذلك من المطالب وقد عرف أن ذلك يحصل بالإخلاص لله وإرادة وجهه, فإذا قصد أن يطلب ذلك بالإخلاص لله وإرادة وجهه كان متناقضا, لأن من أراد شيئا لغيره فالثاني هو المراد المقصود بذاته, والأول يراد لكونه وسيلة إليه

فإذا قصد أن يخلص لله ليصير عالما أو عارفا أو ذا حكمة أو صاحب مكاشفات وتصرفات ونحو ذلك, فهو هنا لم يرد الله بل جعل الله وسيلة له إلى ذلك المطلوب الأدنى

“And that is because a person’s intention becomes (solely) the attainment of knowledge or wisdom, or to seek out hidden matters, or to gain popularity with the people and gain their praise etc. He knows that he can only achieve all that by being sincere to Allah and seeking His Face. So if he seeks these things (praise, gaining knowledge etc) by the token of sincerity to Allah and seeking His Face, then such a person contradicts himself because whoever seeks something (e.g. being sincere to Allah) for the sake of something else (e.g. gain understanding/knowledge), then the latter becomes his real goal and the first is just a means to that.

So if a person intends to be sincere to Allah so that he may become a scholar, or pious, or one endowed with wisdom, or one who discovers hidden realities etc, then such a person does not intend Allah, rather he has made Allah a means for him to gain that inferior matter…”

– From the book درء تعارض المنقول مع صريح المعقول by Ibn Taymiyyah (rahimahullah).

– Incredible. It’s such a subtle difference in intention (although not always blameworthy) but it really makes one appreciate and realise the reasons why the Prophet (sallallahu `alayhi wa sallam) feared Riyaa’ for this Ummah so much. Ibn Taymiyyah’s statement above is not really rebuking people who take such a route, but it’s highlighting the great difference between doing something for the Sake of Allah Alone and doing it in order to attain something specific (even though it may be praiseworthy and permissible). This difference is what brings out the true Mukhliseen (sincere) from the Salihin (righteous).