The way of Faith and Trust in Allah is the way of freedom from the power and control of the Shaitan
Verses 99 and 100 make it clear that Allah Ta’ ala has not given the Shaitan the kind of power which would disarm any human being and compel him to become helpless and take to evil. So, should one opt for not using his capability of choice and control because of sheer carelessness or some selfish motive, then, this would be his own fault. Therefore, it was said that people who have faith in Allah and who, rather than trust their will power in their states and actions, place their ultimate trust in Allah Ta’ ala for He is the One who gives us the ability to do everything good and also the One who shields us from everything evil. The Shaitan cannot possess and dictate such people. Of course, those who elect to befriend none but the Shaitan because of their selfish motives, particularly like things about him and go about associating others in the pristine divinity of Allah Ta` ala, then, the Shaitan is all over them, in possession, in control, and would not let them go towards anything good while, in every evil, they are right in front.
The same subject has been taken up in verse 42 of Surah al-Hijr where Allah Ta’ ala has Himself refuted the claim of the Shaitan by saying: إِنَّ عِبَادِي لَيْسَ لَكَ عَلَيْهِمْ سُلْطَانٌ إِلَّا مَنِ اتَّبَعَكَ (Surely, My servants [ are such that ] you have no power over them - except [ over ] the one who follows you from among the astray - 15:42).