What is the ruling on someone whose source of money is from illicit means, and he cannot stop this work because his family relies on him, yet he is committed to his prayers? Will he be tormented in his grave and be among the people of Hell? Or are his prayers useless because of his illicit source of income?

The questioner must repent to Allah and abandon unlawful earnings, for a body nourished by ill-gotten gains is threatened with Hellfire. Moreover, consuming unlawful earnings is a reason for prayers not being answered. As for the matter of punishment or lack thereof, this knowledge rests solely with Allah. He may forgive whom He wills and punish whom He wills, and this is the situation of disobedient Muslims.