Kriya is an ancient science,” Yogananda writes. Mahavatar Babaji rediscovered and clarified the technique after it had been lost in the Dark Ages. Babaji revealed to Lahiri Mahasaya: “The Kriya Yoga which I am giving to the world through you in this nineteenth century is a revival of the same science which Krishna gave, millenniums ago, to Arjuna, and which was later known to Patanjali, and to Christ, St. John, St. Paul, and other disciples.