Jarir, the son of Abdullah, said: “We pledged in the presence of the Prophet to perform the obligatory prayers, to pay the due Zakat, and to advise and support every Muslim. Related by Bukariyy and Muslim.
To follow the advice of our dear Prophet sallallahu ^alayhi wa sallam is a very beneficial and helpful matter. An example of this is when you witness a Muslim committing a sin, you should advise him in private to stop the sin and repent, and then if he does you should not backbite or slander him. Imam Ahmad Ar-Rifa^iyy explained to us how best to fight the devil.
He said: Fight the devil through advising, supporting, and defending one another.