Someone posted this question in class, during the past few classes, and the question has not yet been answered. Maybe this will help answer the question for that student inshaAllah.
The question was: "From the book titled "Things that Nullify ones Islam" by Shaykh Muhammad ibn 'Abdil-Wahhaab (rahimullah), explained by Ṣāliḥ al-Fawzān (hafidthullah).We can find the 5th principle saying: "Whoever hates something that the Messenger came with, even if he acts according to it, then He has disbelieved. Say someone is dressing according to the Sunnah but is not completely satisfied with the way he looks with the beard and shortened pants, is he among those described in the excerpt above?"
In the book "Al-Adhkaar" by: Imām an-Nawawi, in the chapter of gaurding the tongue it says:
The prophet (salallahu alayhi wa salam) said: "indeed, Allah has permitted for my ummah, that which their souls whisper to them, so long as they do not speak it out (audibly) or act upon it." (Bukhari & Muslim)
The scholars said: "This refers to the notions that form in one's mind, but do not become settled or established there."
And they said: "This is regardless if the notion consists of backbiting, disbelief or so on (i.e. it is pardoned, so long as it does not settle). So (for example) whoever's mind becomes flooded with thoughts of disbelief, but they are only thoughts, without him intending to have them carried out, and he then rids himself of these thoughts right after they occur, he is not a disbelieiver nor is there any sin on him..."