Babaji is an astounding character, one of those immortal beings who operated in the privacy of human history, always behind the scenes, guiding great saints to become even greater, without any public or formal acknowledgement of his role in their development as saints.
he's been alive on the planet since the 200s, showing up here and there, to various spiritual seekers who're of a high enough level to benefit from his training directly.
Yogananda was permitted, in his autobiography, to tell a few (very few) stories about Babaji -- certainly enough to give an idea of the immense divine fragrance that is Babaji.
he also mentioned that Jesus and Babaji, together, are running this planet and taking care of the evolution of the souls on it, for a great and loving divine purpose.
Jesus committed to take care of the souls in the West, and Babaji committed to take care of the souls in the East.
nobody meets Babaji in person without being a high divine character themselves. he lives in the Himalayas, surrounded by a close group of students, and they all move together at one time (by vanishing physically and popping up in another location) when Babaji taps his staff on the ground!
clearly Babaji is a tough-love master who doesn't waste his time with unclear or undedicated spiritual seekers. one of the stories Yogananda tells about him in Autobiography of a Yogi seems, on the surface, harsh:
Babaji and a group of students are sitting around in the Himalayas when a seeker comes up, who's been searching for Babaji for most of his life. he begs Babaji to "please, please accept me as your student. if you don't accept me to be your student, I will kill myself by jumping off that cliff."
Babaji takes one look at the guy and says, "jump, then!"
and without a second thought, the guy jumps off the cliff and falls to his death.
Babaji's students, witnessing this, are aghast. shocked. one of them says, "but Master, wasn't that a little extreme?"
Babaji's response is to laugh, and lead all his students to the base of the mountain where the wannabe's body is lying. he raises that body from the dead, brings the would-be student back to life, and then, grinning, tells him, "NOW you can be my student. that was the final test of your sincerity." and welcomes the guy into his select group of students.
to me, having been in India and learned a lot about spirituality through Kaleshwara, my teacher, and HIS master, Shirdi Sai Baba, I recognize Babaji's no-holds-barred style of teaching as a Dattatreya mechanism.
Dattatreya is the ultimate guru -- in fact, ALL guru lineages to back to him, no matter what religion, what tradition it is, today. they all flow back to the original teacher, Dattatreya.
Shirdi Sai Baba, Kaleshwara's master and my own sat-guru, ultimate master, is an incarnation of Dattatreya.
Datta is an unbelievable character, who contains all the three divine cyclic qualities IN him. he's often shown as having three heads, one for Brahma (the creator), one for Vishnu (the maintainer) and one for Shiva (the destroyer).
another way to think of this trinity of the godhead is:
Shirdi Sai Baba and other Datta saints manifest all three qualities of the god energy, at different times, for different reasons -- sometimes they're high-energy, amazing knowledge and creator characters. at other times, they're sweetness, love, kindness and generosity embodied. at other times, they are relentless and rough, sharp and even (seemingly) ruthless -- destroying the egoism and the illusions of their students.
the story of Babaji telling that guy to jump over the cliff and die is, to me, a CLASSIC Dattatreya mechanism -- it's a challenge to that student's clarity and surrendered-ness to the divine. if that student had hesitated for a moment, had responded to Babaji by saying, "JUMP? are you crazy!???" or protested in any way -- no way he would've been accepted as Babaji's student.
it seems crazy to the rational mind, how someone could have such a blind faith in a spiritual master that they would literally be willing to die at a moment's notice on the orders of that master -- but spirituality, in Dattatreya's beautiful hands, is a matter of real surrender, no matter what god is asking.
and of course -- the inevitable amazing outcome of the story, Babaji raising that man from the dead, right in front of his astonished students' eyes, and then welcoming him with open arms as a great student... that's the real love, the real divine fragrance, the real Datta mechanism.