People are generally awed by the revelation of things belonging to the spiritual realm or by future events. None of these is a Deeni excellence. Being a Muslim and having sanity are not even requisites for such phenomena.
Kashf (inspirational revelation) occurs to even non-Muslims and insane persons. Kashf in general is the effect of a natural capacity in some people, in even kuffaar, fussaaq and insane persons. It has no relation to piety.
People are enamoured by marvellous demonstrations. They quickly develop faith in a man of kashf. Many among such persons are astray and mislead others.
The only criterion of Haqq and Baatil (Truth and falsehood) is obedience to the Shariah and Sunnah. A man who does not conform to this standard cannever be a Wali (Saint) irrespective of the abundance of his miraculous displays and incidences of kashf.
(Maulana Ashraf Ali Thanvi)