First you must find a teacher, a true teacher, and you must remember that he is not just a man. You may get a teacher in the body, but the real teacher is not in the body; he is not the physical man—he is not as he appears to your eyes. It may be the teacher will come to you as a human being, and you will receive the power from him. Sometimes he will come in a dream and transmit things to the world. The power of the teacher may come to us in many ways. But for us ordinary mortals the teacher must come, and our preparation must go on till he comes.
We attend lectures and read books, argue and reason about God and soul, religion, and salvation. These are not spirituality, because spirituality does not exist in books or in theories or in philosophies. It is not in learning or reasoning, but in actual inner growth. . . . So when real light will come there will be no more of this learning from books—no book learning. The man who cannot write even his own name can be perfectly religious, and the man with all the libraries of the world in his head may fail to be. Learning is not a condition of spiritual growth; scholarship is not a condition. The touch of the guru, the transmittal of spiritual energy, will quicken your heart. Then will begin the growth. That is the real baptism by fire. No more stopping. You go on and go on.
The guru must teach me and lead me into light, make me a link in that chain of which he himself is a link. The man in the street cannot claim to be a guru. The guru must be a man who has known, has actually realized the divine truth, has perceived himself as the spirit. A mere talker cannot be a guru. . . . A true guru will tell the disciple, “Go and sin no more,” and no more can he sin—no more has the person the power to sin. . . . The power that can transform life in a moment can be found only in the living illumined souls, those shining lights who appear among us from time to time. They alone are fit to be gurus.
‒ Swami Vivekananda
“Discipleship,” Complete Works, Vol. VIII