Can God mislead a righteous servant who is without sin, as a trial to see the extent of his adherence to his religion and his resistance to deviation?

Allah misguides whom He wills and guides whom He wills, by His wisdom. The predestination of sins and evil deeds holds profound wisdoms that most of creation are incapable of comprehending. The affliction of a servant with sin or misguidance might be a test and a means of drawing him closer to his Lord, so he increases in proximity, reliance, and humility. Indeed, Allah loves repentance and rejoices in it. He might decree sin for His servant to test him; if the good has been preordained for him, He grants him success in repentance, otherwise, He establishes the proof against him. Among the wisdoms of predestining sins is to elicit the servant's seeking refuge and assistance from his Lord, and various forms of supplication and humble entreaty, thereby attaining a special closeness that would not have been achieved otherwise. Through this, Allah also extracts from His servant the perfection of his servitude and his realization of the true nature of his oppressive and ignorant self, and that all goodness comes from Allah. The lesson lies in the perfection of the servant's end, not in the imperfection of his beginning.