In the name of Allah, the Beneficent, the Merciful
Al-Nawawi records in his book, Riyad us-Saliheen:
Allah said:
إِنَّمَا الْمُؤْمِنُونَ إِخْوَةٌ فَأَصْلِحُوا بَيْنَ أَخَوَيْكُمْ وَاتَّقُوا اللَّهَ لَعَلَّكُمْ تُرْحَمُونَ
The believers are brothers, so reconcile between your brothers, and fear Allah that you may receive mercy.
Surah Al-Hujurat 49:10
And Allah said:
أُبَلِّغُكُمْ رِسَالَاتِ رَبِّي وَأَنصَحُ لَكُمْ
Noah said: I convey the message of my Lord to you and I sincerely advise you.
Surah Al-A’raf 7:62
And Allah said:
أُبَلِّغُكُمْ رِسَالَاتِ رَبِّي وَأَنَا لَكُمْ نَاصِحٌ أَمِينٌ
Hud said: I convey the message of my Lord to you and I am to you a trustworthy adviser.
Surah Al-A’raf 7:68
Tamim Ad-Dari reported: The Messenger of Allah, peace and blessings be upon him, said:
الدِّينُ النَّصِيحَةُ
Religion is sincerity.
It was said, “To whom?” He said:
لِلَّهِ وَلِكِتَابِهِ وَلِرَسُولِهِ وَلِأَئِمَّةِ الْمُسْلِمِينَ وَعَامَّتِهِمْ
To Allah, His Book, His Messenger, the leaders of the Muslims, and their common people.
Source: Sahih Muslim 55, Grade: Sahih
Jareer ibn Abdullah, may Allah be pleased with him, said:
بَايَعْتُ رَسُولَ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ عَلَى السَّمْعِ وَالطَّاعَةِ وَأَنْ أَنْصَحَ لِكُلِّ مُسْلِمٍ
I swore allegiance to the Messenger of Allah, peace and blessings be upon him, pledging to listen and obey and to be sincere to every Muslim.
Source: Sahih Muslim 88, Grade: Sahih
Anas ibn Malik reported: The Prophet, peace and blessings be upon him, said:
لَا يُؤْمِنُ أَحَدُكُمْ حَتَّى يُحِبَّ لِأَخِيهِ أَوْ قَالَ لِجَارِهِ مَا يُحِبُّ لِنَفْسِهِ
None of you has faith until he loves for his brother or his neighbor what he loves for himself.
Source: Sahih Bukhari 13, Grade: Muttafaqun Alayhi
Success comes from Allah, and Allah knows best.