Shaikhul Islaam Ibn Taymiyyah [rahimahullaah] said:

When a person does not act on truth he is in needs of-neither affirming nor loving it, he is an oppressor against himself. When he affirms falsehood or loves it, and follows his desires, he is an oppressor against himself. Oppression against oneself returns back to following conjecture and what the soul desires, and this can be by way of following one’s views and desires. Bidah is the basis of evil and that is to give precedence to one’s intellect over the revealed text and choosing one’s desires over the fulfilment of a command. Following the guidance is the basis of good, as Allaah (The Most High) said:

فَإِمَّا يَأۡتِيَنَّڪُم مِّنِّى هُدً۬ى فَمَنِ ٱتَّبَعَ هُدَاىَ فَلَا يَضِلُّ وَلَا يَشۡقَىٰ

وَمَنۡ أَعۡرَضَ عَن ذِڪۡرِى فَإِنَّ لَهُ ۥ مَعِيشَةً۬ ضَنكً۬ا وَنَحۡشُرُهُ ۥ يَوۡمَ ٱلۡقِيَـٰمَةِ أَعۡمَىٰ

”Then if there comes to you guidance from Me, then whoever follows My Guidance shall neither go astray, nor fall into distress and misery. But whosoever turns away from My Reminder (i.e. neither believes in this Qur’an nor acts on its orders, etc.) verily, for him is a life of hardship, and We shall raise him up blind on the Day of Resurrection.” [Taha Aayat 123-124]


[Source: شرحُ حديث ٱللهم إني ظلمت نفسي ظلما كثيرا of Shaikhul Islaam Ibn Taymiyyah. Page: 66]