Say, "Have you considered: if the Qur'an is from Allah and you disbelieved in it, who would be more astray than one who is in extreme dissension?"  

قُلْ أَرَأَيْتُمْ إِنْ كَانَ مِنْ عِنْدِ اللَّهِ ثُمَّ كَفَرْتُمْ بِهِ مَنْ أَضَلُّ مِمَّنْ هُوَ فِي شِقَاقٍ بَعِيدٍ  

We will show them Our signs in the horizons and within themselves until it becomes clear to them that it is the truth. But is it not sufficient concerning your Lord that He is, over all things, a Witness?  

سَنُرِيهِمْ آيَاتِنَا فِي الْآفَاقِ وَفِي أَنْفُسِهِمْ حَتَّىٰ يَتَبَيَّنَ لَهُمْ أَنَّهُ الْحَقُّ ۗ أَوَلَمْ يَكْفِ بِرَبِّكَ أَنَّهُ عَلَىٰ كُلِّ شَيْءٍ شَهِيدٌ  

Unquestionably, they are in doubt about the meeting with their Lord. Unquestionably He is, of all things, encompassing.  

أَلَا إِنَّهُمْ فِي مِرْيَةٍ مِنْ لِقَاءِ رَبِّهِمْ ۗ أَلَا إِنَّهُ بِكُلِّ شَيْءٍ مُحِيطٌ