Imam al-Sadiq (AS) said, ‘He who suspects the religion of his brother removes the covenant between them.
الإمامُ الصّادقُ (عَلَيهِ الّسَلامُ): مَنِ اتَّهمَ أخاهُ في دِينِهِ فلا حُرمَةَ بَينَهُما .
Similar narrations
Al-Kāfi #1324“I heard Abu ‘Abdillah (a.s.) saying, ‘Whenever one accuses his brother (in belief) in his religious matters, religious relations will cease...