From the book Ann-ul- Hiat, Chapter on Innovation
It is narrated from Imam Hassan Askaria.s that Imam Ali bin Hussain (a.s) said: When you learn about a scholar who looks like a ‘Alam-e-Deen’, from his appearance, who replies to questions after extensive thinking and taking careful measures and greets with affability and observes humbleness-don’t be simply taken over by these qualities as many people would like to corrupt ‘Deen’ for the sake of worldly benefits, they trick sincere worshiper into their devious web, and rob them from their wealth and once they mange to do so, they get pleasure from their accumulated wealth. However, when you find an ‘Alam’ who refrains from worldly gains and observes religious acts and controls his desires even then do not get trapped in their masquerading manners as there could be many types of ego related desires, hidden underneath! Since an ‘Alam’ keeps away from the unjust wealth but may still be engulfed by other un-Islamic practices. When you confirm that he is not indulged into any of these, even then be careful and take further precautions before trusting him! Until you yourself, do not verify that his practices are according to his preaches and he has sound knowledge- and these should appreciably be reflected from him. The unwise among them (Alam), however, do more harm to the Deen through their critical mistake than any good even when they intend to act with good intentions. And when you make sure that his wisdom is credible even then do not be deceived by him and see if his wisdom keeps control of his wild and filthy desires and see whether he likes the worldly positions and the tendency to be praised by people. As there are few who would trade their ‘Deen’ for worldly gains but end up loosing both of them. Few of them, strife for status, popularity and position at the cost of sacrificing all comforts of their lives. Allahswt would stop His mercy unto them due to their sins and leave them astray in the darkness. They declare Allahswt’s ‘Hallal’ as Harram and Harram is converted into Hallal. Worldly glory and power glitter their eyes and they do not hesitate to trade the Deen to acquire them. They are the ones who will be severely cursed and punished by Allahswt and there is humiliating wrath of Allahswt awaiting them. The brave one is that who holds back his desires in obedience of Allahswt and exerts all his energy as per Commands of Allahswt, He firmly believes in the everlasting respect and bounties of the hereafter as compared with the short lived admiration earned in this world. And the pain and grief experienced in the way of Deen-e-Haq, is minuscule as compared with the pleasures of the garden of paradise. He who has these quality is a ‘Mard-e-Kamil’ (true believer) and worth following! His all prayers are answered by the Allahswt and his all requests are granted by Him.