(His Divine Grace Srila Prabhupada—click to enlarge)
"The service of the spiritual master is essential. If there is no chance to serve the spiritual master directly, a devotee should serve him by remembering his instructions. There is no difference between the spiritual master's instructions and the spiritual master himself."
(Caitanya-caritāmṛta Ādi 1.35, Purport)
"There are two conceptions: the physical conception and the vibration conception. So physical conception is temporary. The vibration conception is eternal. Just like we are enjoying or we are relishing the vibration of Kṛṣṇa's teachings. So by vibration He is present. As soon as we chant Hare Kṛṣṇa or chant Bhagavad-gītā or Bhāgavata, so He is present immediately by His vibration. He's absolute. Therefore try to remember His words of instruction; you'll not feel separation. You'll feel that He is with you. So we should associate by the vibration, and not by the physical presence. That is real association. Śabdād anavṛtti. By sound. Just like we are touching Kṛṣṇa immediately by sound. Sound vibration. So we should give more stress on the sound vibration, either of Kṛṣṇa or of the spiritual master. Then we'll feel happy and no separation.
When Kṛṣṇa departed from this world, at that time Arjuna was overwhelmed with sorrow and he began to remember the instruction of Bhagavad-gītā. You'll find in the Śrīmad-Bhāgavatam. Then he was pacified. He immediately began to remember the teachings which was taught to him in the Battlefield of Kurukṣetra, and he was pacified. He was his constant friend, so when Kṛṣṇa went to His abode he was feeling overwhelmed, but he began to remember His teaching. So whenever we shall feel separation, the best thing is to remember the teachings. Then it will be very nice. Is that clear? Yes."
(Srila Prabhupada Lecture, Montreal, August 18, 1968)
"I went to your country for spreading this information of Krishna Consciousness & you are helping me in my mission although I am not physically present there but spiritually I am always with you."
(Srila Prabhupada Letter, October 3, 1967)
"My Guru Maharaja used to say that there is no scarcity of anything in this world, save and except Krishna Consciousness. Keep your present attitude, intact; have good faith in your Spiritual Master and Krishna and everything will be all right. You have already taken this secret of success, sincerity, and pull on with that mentality. And Krishna will give you all help.
You write to say, 'I really miss Swamiji and my God-brothers' association so much.' But I may remind you that I am always with you. And so wherever I am there, and you are there, all your God-brothers are there. Please remember always the humble teachings that you have received from me, and that will make you always associated with me, and with your other God-brothers."
(Srila Prabhupada Letter, August 24, 1968)
"But always remember that I am always with you. As you are always thinking of me, I am always thinking of you also. Although physically we are not together, we are not separated spiritually. So we should be concerned only with this spiritual connection."
(Srila Prabhupada Letter, November 13, 1969)
"There is no difference between me and my picture. Therefore we
should honor and keep pictures in that spirit. If we throw pictures
this way and that way, that is offence. The name and picture are as good as the person in spiritual world. In the material world either picture or person, everything is illusion."
(Srila Prabhupada Letter, September 4, 1972)
"As far as my blessing is concerned, it does not require my physical presence. If you are chanting Hare Krishna there, and following my instructions, reading the books, taking only Krishna prasadam etc., then there is no question of your not receiving the blessings of Lord Caitanya, whose mission I am humbly trying to push on."
(Srila Prabhupada Letter, June 30, 1974)
Devotee: Śrīla Prabhupāda, when you are not present with us, how is it possible to receive instructions, for example, on questions that may arise?
Prabhupāda: Well, the questions are... Answers are there in my books.
Devotee: Other than that, for example, that we would ask you in...
Devotee: Do you direct us also through the heart? Besides the Paramātmā?
Prabhupāda: If your heart is pure. Everything depends on purity.
(Srila Prabhupada Morning Walk, Los Angeles, May 13, 1973)
Reporter: What will happen to the movement in the United States when you die?
Prabhupāda: I will never die.
Devotees: Jaya! Hari bol! (laughter)
Prabhupāda: I shall live for my books, and you will utilize.
(Srila Prabhupada Press Conference, San Francisco, July 16, 1975)