Is it permissible for this man, who disbelieves, offends, utters words of disbelief, and steals water, to live with my grandmother and us, and what should we do about that and about drinking the water he steals?

If a man's disbelief is established, his wife is not permitted to remain married to him. His children must strive to guide him and convince him to adhere to the religion and repent from polytheistic utterances and disgraceful acts, so that he may die as a Muslim. If he insists on his disbelief, they should uphold his right to kindness and good companionship, while supplicating for him and not despairing of his repentance and guidance, in accordance with the Almighty's saying: "But if they endeavor to make you associate with Me that of which you have no knowledge, do not obey them but accompany them in [this] world with appropriate kindness." As for stolen water, it must be returned to its owners, and it is not permissible to drink from it. One can negotiate with the water owners to seek their permission or compensate them for what they need from it.