For one thing, there is the matter of language and religious communication. Most Hindi speakers would not have too much difficulty in transcribing the over four thousand sanskrit mantras available to them. But particularly on the Indian sub-continent, not all Hindus have access to these ancient spiritual philosophies and dedications. To compensate, they usually attend the thousands of temples around their country and listen to a few words of wisdom and spiritual counseling from a guru who is usually in the lofty position that he is in through divine intervention.
His inspirational words and recitations become successful because his receptive devotees are affirmative believers. However, it is not only through a spiritual premonition that he gets to lead hundreds or thousands of followers in prayer. To substantiate his life as a true guru, he also has to learn the ancient philosophies derived from the thousands of Sanskrit mantras which are, in fact, now widely available to other interested parties across the world.
His life, as a whole, must also be a pious and wholly religious one. Today, it is the wise and the ignorant that have access to Eastern meditations in alternative published forms. These come by way of internet publications, website introductions and regular social media feeds that give them their daily devotional readings, thoughts for the day and spiritual meditations. Today, thanks to the work of a few qualified and experienced scholars or gurus, many Sanskrit mantras have been translated into a language of choice, mainly in the widely spoken and read English medium.
It is necessary to rely on authority when delving into mysticism and philosophy because the authoritative voice of reason has its foundations in truth as believed by devotees.