Under some circumstances, it would be inappropriate to have fellowship with certain people.
وَهذَا مُهِمٌّ لِأَنَّكَ لَا تَعْرِفُ مَا فِي قَلْبِهِ وَلَا كَيْفَ يُفَكِّرُ ،‏ أَمَّا يَهْوَهُ فَيَعْلَمُ ذلِكَ تَمَامًا .‏