Steadfastness in religion

يَـٰٓأَيُّهَا ٱلَّذِينَ ءَامَنُوٓا۟ إِن تُطِيعُوا۟ فَرِيقًا مِّنَ ٱلَّذِينَ أُوتُوا۟ ٱلْكِتَـٰبَ يَرُدُّوكُم بَعْدَ إِيمَـٰنِكُمْ كَـٰفِرِينَ

O you who have believed, if you obey a party of those who were given the Scripture, they would turn you back, after your belief, [to being] unbelievers.

وَمَا مُحَمَّدٌ إِلَّا رَسُولٌ قَدْ خَلَتْ مِن قَبْلِهِ ٱلرُّسُلُ ۚ أَفَإِي۟ن مَّاتَ أَوْ قُتِلَ ٱنقَلَبْتُمْ عَلَىٰٓ أَعْقَـٰبِكُمْ ۚ وَمَن يَنقَلِبْ عَلَىٰ عَقِبَيْهِ فَلَن يَضُرَّ ٱللَّهَ شَيْـًٔا ۗ وَسَيَجْزِى ٱللَّهُ ٱلشَّـٰكِرِينَ

Muḥammad is not but a messenger. [Other] messengers have passed on before him. So if he was to die or be killed, would you turn back on your heels [to unbelief]? And he who turns back on his heels will never harm Allāh at all; but Allāh will reward the grateful.