Physical presence is immaterial. Presence of the transcendental
sound received from the Spiritual Master should be the guidance of
life. That will make our spiritual life successful. If you feel very
strongly about my absence you may place my pictures on my sitting
places and this will be source of inspiration for you. (Letter to
Brahmananda and other students, 19/1/67)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.
(Letter to Gaurasundara, 13/11/69)

So we should associate by vibration, and not by the physical
presence. That is real association.
(Lectures SB, 68/08/18)

There are two conceptions, the physical conception and the
vibrational conception. The physical conception is temporary. The
vibrational conception is eternal.[…] When we feel separation from
Krsna or the Spirirual Master, we should just try to remember their
words or instructions, and we will no longer feel that separation.
Such association with Krsna and the Spiritual Master should be
association by vibration not physical presence. That is real
association. (Elevation to Krsna Consciousness,(BBT 1973), Page 57)

Although according to material vision His Divine Grace Srila
Bhaktisiddhanta Sarsavati Thakura Prabhupada passed away from this
material world on the last day of December 1936, I still consider
his Divine Grace to be always present with me by his vani, his
words. There are two ways of association – by vani and by vapuh.
Vani means words and vapuh means physical presence. Physical
presence is sometimes appreciable and sometimes not, but Vani
continues to exist eternally. Therefore, one must take advantage of
the Vani, not the physical presence.  (CC, Antya 5 Conclusion)

Therefore we should take advantage of the Vani, not the physical
presence. (Letter to Suci Devi Dasi, 4/11/75)

I shall remain your personal guidance, physically present or not
Physically present, as I am getting guidance from my Guru Maharaja.
(Room Conversation, Vrindavan, 14/7/77)

It is sometimes misunderstood that if one has to associate with
persons engaged in devotional service, he will not be able to solve
the economic problem. To answer this argument, it is described here
that one has to associate with liberated persons not directly,
physically, but by understanding, through philosophy and logic, the
problems of life. (SB 3:31:48)

I am always with you. Never mind if I am physically absent.
(Letter to Jayananda, 16/9/67)

Paramananda: We’re always feeling your presence very strongly, Srila
Prabhupada, simply by your teachings and your instructions. We’re
always meditating on your instructions.
Srila Prabhupada:  Thank you. That is the real presence. Physical
presence is not important.
(Room Conversation, Vrndavana, 6/10/77)

You write that you have desire to avail of my association again, but
why do you forget that you are always in association with me? When
you are helping my missionary activities I am always thinking of
you, and you are always thinking of me . That is real association.
Just like I am always thinking of my Guru Maharaja at every moment,
although he is not physically present, and because I am trying to
serve him to my best capacity, I am sure he is helping me by his
spiritual blessings. So there are two kinds of association: physical
and preceptorial. Physical association is not so important as
preceptorial association. (Letter to Govinda Dasi, 18/8/69)

As far as my blessing is concerned, it does not require my physical
presence. If you are chanting Hare Krsna there, and following my
instructions, reading the books, taking only Krsna 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.
(Letter to Bala Krsna, 30/6/74)

‘Anyone who has developed unflinching faith in the Lord and the
Spiritual Master can understand the revealed scripture unfolding
before him’. So continue your present aptitude and you will be
successful in your spiritual progress. I am sure that even if I am
not physically present before you, still you will be able to execute
all spiritual duties in the matter of Krsna Consciousness, if you
follow the above principles. (Letter to Subala, 29/9/67)

So although a physical body is not present, the vibration should be
accepted as the presence of the Spiritual Master, vibration. What we
have heard from the Spiritual Master, that is living. (General
lectures, 69/01/13)

Devotee: …so sometimes the Spiritual Master is far away. He may be
in Los Angeles. Somebody is coming to Hamburg Temple. He thinks ‘How
will the Spiritual Master be pleased?’
Srila Prabhupada: Just follow his order, Spiritual Master is along
with you by his words. Just like my Spiritual Master is not
physically present, but I am associating with him by his words.
(SB Lectures, 71/08/18)

Just like I am working, so my Guru Maharaja is there,
Bhaktisiddhanta Sarasvati. Physically he may not be, but in every
action he is there. To serve master’s word is more important than to
serve physically. (Room Conversation, Vrindavan, 2/5/77)

So that is called prakata, physically present. And there is another
phrase, which is called aprakata, not physically present. But that
does not mean, Krsna is dead or God is dead. That does not mean,
prakata or aprakata, physically present or not present, it does not
matter. (Lectures SB 73/12/11)

So, spiritually, there is no question of separation, even physically
we may be in far distant place.  (Letter to Syama Dasi, 30/08/68)

I went to your country for spreading this information of Krsna
Consciousness and you are helping me in my mission, although I am
not physically present there but spiritually I am always with you.
(Letter to Nandarani, Krsna Devi and Subala, 3/10/67)

We are not separated actually. There are two – Vani or Vapuh – so
Vapu is physical presence and Vani is presence by the vibration, but
they are all the same.  (Letter to Hamsadutta, 22/6/70)

So in the absence of physical presentation of the spiritual master,
the Vaniseva is more important. My Spiritual Master Sarsavati
Goswami, may appear to be physically not present, but still because
I try to serve his instruction, I never feel separated from him.
(Letter to Karandhara, 22/8/70)

I also do not feel separation from my Guru Maharaja. When I am
engaged in his service, his pictures give me sufficient strength. To
serve master’s word is more important than to serve him physically.
(Letter to Syamasundara, 19/7/70)