Sincerity to the rulers consists of the following: Supplicating for their righteousness and firmness, since it is from the Sunnah to supplicate for the Muslim rulers, especially during times in which the supplication is answered and the places in which it is hoped the supplication is answered.
Al-Fudayl ibn Iyaad said, “If I had a supplication that would be answered I would supplicate for the ruler.” This is because in the rectification of the ruler lies rectification of the society, and in corruption of the ruler lies corruption of the society.
And from sincerity towards the rulers is to establish the duties which they appoint for the employees. And from sincerity towards them is to inform them of mistakes and evils which occur in society, while they are unaware of them. However this should be done privately between the one advising and them. Not the advice which is manifest in front of the people or on the pulpits, because this brings about enmity between the rulers and the ruled.
It not sincere advice that a person should speak about mistakes of the rulers upon the pulpit or on a chair in front of the people, this does not serve the benefit, rather it increases the evil even more. Sincere advice is that you should contact the ruler personally or by writing or by way of those who can contact them and convey your advice privately between you and them. And also it is not from sincere advice that we write criticisms of them and spread them amongst the people and then say this is from sincere advice. No! This is from exposition (of their mistakes) and from those affairs which cause evil, and please the enemies, and it is the people of desires who enter into these matters and ways.