Hazrat Moulana Ashraf Ali Thanwi (rahmatullahi ‘alaih) once mentioned:
Listen attentively to what I am going to say to you. I say this to you with deep concern for your spiritual progress and welfare. There are two factors in this path that are extremely detrimental for the saalik (i.e. the one who is treading the path of acquiring the love of Allah Ta‘ala) and can cause him to become completely deprived of all good. The first is the sickness of covering up for one’s mistakes and presenting interpretations to defend one’s wrongs. The second is the sickness of raising objections against one’s elders, ustaads and spiritual mentors. (Malfoozaat Hakeemul Ummat 8/231)