It is narrated that a man told the third Shia Imam, Hussain ibn Ali (AS):

O’ the son of the Prophet of Allah (SWT), I am one of your Shias. Imam (AS) said: O’ man, fear God and do not claim a thing which God says: You have lied about your claim and you lied! Because our Shias are those whose hearts are free from rancour, cunning, deception, betrayal, and cheating. Then, do not make such a claim that you are one of our Shias, rather say only: I am one of your friends and enthusiasts [1].

[1] Behirul Anwaar, Vol. 65, Page 156.

Source: en.shafaqna.com