Surah Ali 'Imran Verse 85

وَمَنْ يَبْتَغِ غَيْرَ الْإِسْلَامِ دِينًا فَلَنْ يُقْبَلَ مِنْهُ وَهُوَ فِي الْآخِرَةِ مِنَ الْخَاسِرِينَ

And whoever desires other than Islam as religion - never will it be accepted from him, and he, in the Hereafter, will be among the losers