Aisha reported: The Messenger of Allah, peace and blessings be upon him, said:

إِنَّ مِنْ أَكْمَلِ الْمُؤْمِنِينَ إِيمَانًا أَحْسَنُهُمْ خُلُقًا وَأَلْطَفُهُمْ بِأَهْلِهِ

Verily, the most complete of believers in faith are those with the best character and who are most kind to their families.

Source: Sunan al-Tirmidhī