The statement of the Prophet (saws): Religion is An-Nasihah (to be sincere and true) to Allah, to His Messenger (Muhammad (saws)), to the Muslim rulers, and to all the Muslims

Narrated Ziyad bin'Ilaqa:

I went to the Prophet and said, 'I give my pledge of allegiance to you for Islam." The Prophet (ﷺ) conditioned (my pledge) for me to be sincere and true to every Muslim so I gave my pledge to him for this. By the Lord of this mosque! I am sincere and true to you (Muslims). Then Jarir asked for Allah's forgiveness and came down (from the pulpit).