Is it permissible for a Muslim living in a non-Muslim society to participate with non-Muslims in certain places and actions, especially if they believe that Muslims of their generation do not fully practice Islam?

It is not permissible for a Muslim to participate with non-Muslims in their religious observances, such as holidays and fasting, for this entails falling into disbelief (kufr) or major sins, and it may lead to compromising the religion of Allah and strengthening the disbelievers. As for ordinary gatherings that do not include forbidden acts like dancing, singing, and mixing of genders, there is no harm in them, with caution against excessive interaction with disbelievers. It is preferable to adhere to gathering with good Muslims.