Can we judge a person as a true devotee of God, based on his or her behaviour and speech?

[An online spiritual discussion was conducted on March 20, 2021, in which several devotees participated. The questions of devotees answered by Swāmi are given below.]

[Śrī Balaji asked: Namaste Swami! Some devotees respected as gurus seem to get visions from God and have some miraculous powers (siddhis), even though their behaviour can be very egoistic and even though they speak and act without proper analysis. Sometimes, their actions hurt their own followers as they threaten the followers with the anger of God. Hence, the followers are filled with fear and follow blindly, whatever these gurus say. These gurus also criticize some recent Incarnations of God and other gurus, calling them frauds or claiming that they are ignorant of the correct spiritual path. How are such gurus able to get visions of God, inspite of behaving incorrectly? Do they really have the grace of God and should their followers and other devotees pay the utmost respect to them? Sincerely, Balaji]

Swāmi replied: Assuming that the preacher is wrong, we can only pick up whatever good we find in him. For whatever bad qualities the preacher has, we can let the preacher undergo the punishment that will be given by God, in the course of time. You can analyze the subject preached by the preacher and adopt only the good points that help you progress spiritually. You can neglect the rest because God will deal with him properly at the appropriate time. You need not criticize the preacher. But you can criticize or analyze his preaching.