Read and reflect on verse 144 from Surah Al-Baqara: And if [others] come to believe in the way you believe, they will indeed find themselves on the right path; and if they turn away, it is but they who ...
فَإِنْ آمَنُوا بِمِثْلِ مَا آمَنْتُمْ بِهِ فَقَدِ اهْتَدَوْا ۖ وَإِنْ تَوَلَّوْا فَإِنَّمَا هُمْ فِي شِقَاقٍ ۖ فَسَيَكْفِيكَهُمُ اللَّهُ ۚ وَهُوَ السَّمِيعُ الْعَلِيمُ
And if [others] come to believe in the way you believe, they will indeed find themselves on the right path; and if they turn away, it is but they who will be deeply in the wrong, and God will protect thee from them: for He alone is all-hearing, all-knowing.