So how does one of the world's great atheists and opponents of religion discuss the concept of gurus? Pretty well, actually, probably because he's been exposed to more of them than most people on this forum.
Having realized that he was advising people to learn how to meditate and thus possibly exposing them to the world of spiritual teachers and gurus, he raps at one point about gurus. The result is classic Sam Harris -- the first paragraph is balanced and useful and compassionate, the second is hilariously barbed and IMO right on, and the last sentence conveys the pragmatic bottom line: The gurus I have met personally, as well as those whose careers and teachings I have studied at a distance, range from crooks who could be quickly dismissed to teachers who were brilliant but flawed, to those who, while still human, seemed to possess so much compassion and clarity of mind that they were nearly flawless examples of the benefits of spiritual practice. This last group is of obvious interest, and these are surely the people one hopes to meet, but the middle group can be helpful as well. Some teachers about whom depressing stories are told—men and women whose indiscretions may seem to discredit the very concept of spiritual authority—are, in fact, talented contemplatives. Many of these people get corrupted by the power and opportunities that come from inspiring devotion in others. Some may begin to believe the myths that grow up around them, and some are guilty of ludicrous exaggerations of their own spiritual and historical significance. Caveat emptor. Of course, there can be clear indications that a teacher is not worth paying attention to. A history as a fabulist or a con artist should be considered fatal; thus, the spiritual opinions of Joseph Smith, Gurdjieff, and L. Ron Hubbard can be safely ignored. A fetish for numbers is also an ominous sign. Math is magical, but math approached like magic is just superstition—and numerology is where the intellect goes to die. Prophecy is also a very strong indication of chicanery or madness on the part of a teacher, and of stupidity among his students. One can extrapolate from scientific data or technological trends (climate models, Moore’s law), but most detailed predictions about the future lead to embarrassment right on schedule. Anyone who can confidently tell you what the world will be like in 2027 is delusional. The channeling of invisible entities, whether broadcast from beyond the grave or from another galaxy, should provoke only laughter. J. Z. Knight, who has long claimed to be the mouthpiece for a 35,000-year-old entity named Ramtha, is the ultimate example of how you don’t want your teacher to sound. And any suggestion that a guru has influenced world events through magic should also put an end to the conversation. Sri Aurobindo and his partner, known as “the Mother,” apparently claimed to have decided the outcome of World War II with their psychic powers.9 (In that case, one wonders why they weren’t held morally responsible for not having ended it sooner.) Yet another reason to ignore Aurobindo’s long, unreadable books. Generally speaking, you should head for the door at any sign of deception on the part of a teacher.