What is the correct stance to take with sisters who have uncovered their faces and adorned themselves despite having previously covered themselves? Should their father be informed, considering he is unaware because they cover themselves in front of him? Is he permitted to prevent them from uncovering their faces in his car? What are the hadiths and narrations that speak about the virtue of patience in performing acts of obedience and abandoning sins?

Your sisters must cover their faces when they go out if they are adorned, because it is among what Allah has commanded to be covered. Displaying adornment (tabarruj) is adorning oneself with things that are not customary, such as applying rouge or whitening the face. If this ruling applies to elderly women, then it applies even more so to others. Since you have become aware of this wrongdoing, advise your sisters to increase their faith. If they benefit, then fine; otherwise, threaten them by informing your father. If they do not desist, then inform him, because he is their guardian and must prevent them from going out in that state. He is responsible for them before Allah. The possibility that your father might be harsh with them is not a legitimate religious impediment to informing him. Allah Almighty marvels at the young man who has no inclination towards worldly desires.