Al-Hujurat 49:15 انما المومنون الذين امنوا بالله ورسوله ثم لم يرتابوا وجاهدوا باموالهم وانفسهم في سبيل الله اولايك هم الصادقون ١٥

There is a Difference between a Believer and a Muslim

Allah chastises the bedouins who, when they embraced Islam, claimed for themselves the grade of faithful believers. However, Faith had not yet firmly entered their hearts,

قَالَتِ الاٌّعْرَابُ ءَامَنَّا قُل لَّمْ تُؤْمِنُواْ وَلَـكِن قُولُواْ أَسْل