إنما ذلكم الشيطان يخوف أولياءه فلا تخافوهم وخافون إن كنتم مؤمنين – “It is only Shaytan (Satan) that suggests to you the fear of his Auliya’ [supporters and friends (polytheists, disbelievers in the Oneness of Allah and in His Messenger, Muhammad)], so fear them not, but fear Me, if you are (true) believers.” – 3:175
Regarding this verse, Sayyid Qutb said in ‘Fi Dhilal al-Qur’an’:
“Indeed, it is Satan who tries to make his allies a source of fear and terror, and to dress them up with the appearance of power and awe. As a result, the believers should be aware of the plot of Satan and impede his attempts. They should not fear these allies of his. Rather, they should fear Allah alone, as He alone is the Mighty, Overwhelming, and Able who should be feared: “It is only Satan that suggests to you the fear of his allies. So, do not fear them, and fear Me if you are believers.”
Indeed, Satan is the one who inflates the reputation of his allies and dresses them up with the garments of power and ability, and implants in our hearts the idea that they have the ability to do this and that, and that they can bring about benefit and harm. He does all this to fulfill his own interests: to use them to spread evil and corruption on Earth, as well as to cause people to bow down to them and submit their hearts to them so that nobody would say a word of opposition to their faces, and that nobody would even think of criticizing them or preventing them from evil and corruption.
Satan has an interest in falsehood and evil becoming widespread, and that he appear strong, capable, overwhelming, aggressive, and tyrannical so that no opposition stands to his face, nobody repels him, and nobody overpowers him. Satan has an interest in maintaining things this way. So, under the umbrella of fear, terror, and aggression, his allies carry out on Earth that which brings joy to his eyes! They make good appear as evil and evil appear as good. They spread corruption and falsehood and deception. They stifle out the voice of truth, guidance, and justice. They set themselves up as gods on Earth to support evil and kill off good without anyone daring to confront them or stand up to them or expel them from their positions of power – in fact, without anyone pointing out the falsehood that they have beautified or beautifying the truth that they have painted as ugly.
And Satan is a deceptive plotter who hides behind his allies and spreads fear through them into the hearts of those who fail to protect themselves from his whispers. Here, Allah exposes him and stands him naked without any covering for his plots, and makes his reality plain and clear to the believers – the reality of his plots and whispers – so that they are aware of them. So, they do not fear the allies of Satan, as they are too weak to be feared by a believer who relies on his Lord and His Power.
Indeed, the only power that is to be feared is the power that has the ability to bring about benefit and harm. It is the Power of Allah, and it is the Power that the believers in Allah fear. When they fear it alone – the greatest Power of all powers – no force on Earth can stand in front of them – neither the power of Satan nor the power of the allies of Satan…“
See also: https://abdulmaliklive.wordpress.com/2016/07/13/why-do-true-believers-only-fear-god/