How should you react? Out of Christian interest in that person and out of loyalty to Jehovah, you may choose to speak with him in a kindly way, with the aim of winning him over.
بِدَافِعِ ٱلِٱهْتِمَامِ بِهِ وَٱلْوَلَاءِ لِيَهْوَه ،‏ قَدْ تُقَرِّرُ أَنْ تَتَكَلَّمَ مَعَهُ بِلُطْفٍ بِهَدَفِ رِبْحِهِ .‏