The ātman, stripped off the mind, body and senses is a formless conscious being consisting of potentialities of thought, desire and action. All ātmans are identical, with the only difference being their existence as individual ātmans.
We have seen that the ātmans have been wedded to individual minds from beginningless time, and such conditioned ātmans are called jīvas. Ultimately, the information content which constitutes the concepts carried by the mind, differentiates one jīva from another. Concepts then are all important, and more important then a particular jīva. Because concepts drive actions, and actions bring good or bad results.
Not recognizing these basic truths can lead to disaster. In the field of Hinduism in particular, the modern guru tends to be valued for their charisma instead of the concepts he/she espouses and teaches others. Charisma is defined by Max Weber as follows
[A] certain quality of an individual personality, by virtue of which he is set apart from ordinary men and treated as endowed with supernatural, superhuman, or at least specifically exceptional powers or qualities. These are such as are not accessible to the ordinary person, but are regarded as of divine origin or as exemplary, and on the basis of them the individual concerned is treated as a leader. Read more here.
If the guru is able to elicit emotion in their audience, whether through their smiles, hand gestures, mystical glances or well-rehearsed lectures spoken in an emotive voice, then they are considered authentic. Charisma, however, is not a substitute for learning. Concepts are all important, in fact, they are critical. History is littered with examples of charismatic people who led their followers into ignorance, instead of taking them into the light of knowledge.
A guru ought to be valued for the concepts they believe in and teach others, and not their looks, the dreamy quality of their voice, or the emotions they elicit in an audience. Because it is concepts which determine success or failure of any path.
It also follows, that no matter how popular or charismatic a person is, if they teach concepts which contradict scripture, they ought to be summarily rejected.