Rejection of alternative paths to salvation

وَمَن يَبْتَغِ غَيْرَ ٱلْإِسْلَـٰمِ دِينًا فَلَن يُقْبَلَ مِنْهُ وَهُوَ فِى ٱلْـَٔاخِرَةِ مِنَ ٱلْخَـٰسِرِينَ

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