How should one deal with Muslims who do not pray or who commit sins? Should one treat them kindly or keep away from them for fear of temptation? To what extent is it permissible to maintain ties of kinship with relatives residing in Europe who do not adhere to Islamic guidelines? And what is the ruling on inviting non-Muslims to a meal?

Your duty towards negligent brothers is to invite them to Allah with wisdom and good counsel, encouraging them to perform acts of obedience and abandon sins, especially prayer. If they do not respond, then it is obligatory to keep away from them and shun them, and to choose righteous company. As for relatives, you must maintain ties with them and invite them in the best manner, clarifying the impermissibility of shaking hands (with non-mahram women), and urging them to adhere to the guidance of the Prophet, peace and blessings be upon him, while avoiding anything that leads to temptation.