The Prophet ﷺ said: The most perfect believer in respect of faith is he who is best of them in manners. (Using translation from Abū Dāʾūd 4682)
قَالَ رَسُولُ اللهِ ﷺ إِنَّ مِنْ أَكْمَلِ الْمُؤْمِنِينَ إِيمَانًا أَحْسَنَهُمْ خُلُقًا وَأَلْطَفَهُمْ بِأَهْلِهِ