What should a son do when his father compels him to sit with relatives who shun the Sharia and resort to "science and logic" in worldly discussions, saying, "Leave religion aside," and participate in dubious and usurious matters?

One is not obliged to obey the father in sitting with people who commit or utter reprehensible acts and do not desist from them, or in adopting their sayings and acting upon them. Sitting with them is forbidden by divine law, as stated in the Almighty's words: "And He has already revealed to you in the Book that when you hear the verses of Allah being disbelieved in and ridiculed, do not sit with them until they engage in another conversation. Indeed, in that case, you would be like them." Obedience to the father is due in what is good and permissible, not in what Allah has forbidden.