"An avatar lives in the omnipresent Spirit; for him there is no distance inverse to the square. Only one reason, therefore, can motivate Babaji in maintaining his physical form from century to century: the desire to furnish humanity with a concrete example of its own possibilities. Were man never vouchsafed a glimpse of Divinity in the flesh, he would remain oppressed by the heavy mayic delusion that he cannot transcend his mortality."
"Whenever anyone utters with reverence the name of Babaji," Lahiri Mahasaya said, "that devotee attracts an instant spiritual blessing."
Babaji means father and Amma means mother. The Amma I saw in flesh has given me many spiritual blessings. The Babaji i am speaking of has given me a technique of meditation that has helped me understand and experience spirit. It is a privilege and a blessing to be in the presence of a saint or guru. The darshan given by such a being can permanantly change a chela and his or her consciousness. The guru can manifest internally or externally and is not limited by such concepts. A true guru can be formless or in form. These are limiting concepts of the human mind.
http://www.crystalclarity.com/yogananda/chap33.php