وَمَنْ يَبْتَغِ غَيْرَ الْإِسْلَامِ دِينًا فَلَنْ يُقْبَلَ مِنْهُ.
Whoever seeks a religion other than Islam, it will never be accepted from him. (Āl ʿImrān 3:85)
Yabtaghi means to seek or choose, while fa-lan yuqbala minhu states that the religion will not be accepted.
Affirming Islam as the true religion is more than claiming a label; it includes accepting its guidance. The verse does not present an alternative religion as another independently accepted path.