Excerpts from Japa Yoga by Swami Sivananda (p.20-21)
If you utter the word “exceta” or “urine” when your friend is taking his meals, he may at once vomit his food. If you think of “Garam Pakoda” , “hot Pakoda”, your tongue will get salivation. There is a Sakti in every word. When such is the case with ordinary words, how much more power or Sakti should there be in the Name of God – HARI, RAMA, SIVA, or KRISHNA? Repetition or thinking of His Name produces a tremendous influence on the mind. It transforms the mental substance, “Chitta”, overhauls the viciouos old Samskaras in the mind, transmutes the Asuric or diabolical nature and brings the devotee face to face with God. There is no doubt about this. O skeptics and scientific atheists! Wake up! Open your eyes. Chant His Name always. Sing. Do Kirtan.
It is only “Nama-Smarana” that is free from difficulties and troubles. It is easy, comfort-giving and simple. It is said to be the “head”, the “King” of all Sadhanas (means to God-realisation).