Śrīla Bhakti Sundar Govinda Dev-Goswāmī Mahārāj explains why the Lord appears in His Deity form.
When Śrī Śrī Gāndharvā-Govindasundar manifested in Śrī Chaitanya Sāraswat Maṭh, Śrīla Guru Mahārāj composed this verse for the invitation to the festival:
chid-dhāma-sevāmaya-dṛṣṭi-yoge
sevā-vibhāvaiś cha sadā samṛddham
śrī-nāma-rūpaiś cha guṇair vilāsair
bhakte chidānanda-ghanaṁ tanoti
(Śrīla Bhakti Rakṣak Śrīdhar Dev-Goswāmī Mahārāj)
The Lord’s Name, the Lord’s Form, the Lord’s Qualities, and the Lord’s Pastimes are all transcendental, and transcendental existence can manifest itself at any time in any direction. We know that the Lord’s Name is the transcendental vibration form of the Lord, and this form of the Lord manifests in the clean heart of a devotee and then dances on their tongue. Śrīla Bhakti Vinod Ṭhākur said in his song,
kṛṣṇa-nāma dhare kata bala
viṣaya-vāsanānale mora chitta sadā jvale
ravi-tapta maru-bhūmi-sama
karṇa-randhra patha diyā hṛdi mājhe praveśiyā
variṣaya sudhā anupama
hṛdaya ha-ite bale jihvāra agrete chale
śabda-rūpe nāche anukṣaṇa
(Śaraṇāgati: Śrī Nāma-māhātmya, 1–2)
[“How much power does Kṛṣṇa’s Name possess? My heart constantly burns in the fire of mundane desire like a desert scorched by the blazing sun. The Name enters the core of my heart through the gateway of my ears and showers incomparable nectar. Forcibly, the Name then moves from my heart to the tip of my tongue and continuously dances there in the form of sound.”]
Similarly, the Lord’s Name, Form, Qualities, and Pastimes all very mercifully appear in the form of the Deity; everything that exists in the Pastimes of Kṛṣṇa is present with the Deity, and when the Deity manifests Himself, He gives His devotees chid-ānanda-ghanaṁ: eternal concentrated transcendental ecstasy. This is the description given by Śrīla Guru Mahārāj in his sanskrit composition. Why does the Deity manifest? To give the most concentrated form of transcendental ecstasy to the devotees.
The Lord’s Pastimes are revealed to the devotees in the form of Deity. In this way, Kṛṣṇa’s gives the gift of Himself to this mundane world. This is the vision of the Gauḍīya sampradāya. Śrīpād Mādhavendra Purī saw the forms of Gopāl and Gopīnāth with this vision, and wherever He went, Śrīman Mahāprabhu always saw with this vision and showed it others. That the Lord manifests Himself in the form of the Deity to give joy to the hearts of the devotees means that the Deity comes to take our service and that service is what gives us joy. In other words, through our service to the Deity, we will feel joy that is transcendental. All joy of this type is nitya-līlā; it is part of the Lord’s eternal Pastimes.
Those who cannot conceive of the Deity, however, must at least honour the scriptural evidence about the Deity. Otherwise, they will go to hell.
archchye viṣṇau śilā-dhīr guruṣu nara-matir vaiṣṇave jāti-buddhir
viṣṇor vā vaiṣṇavānāṁ kali-mala-mathane pāda-tīrthe ‘mbu-buddhiḥ
śrī-viṣṇor nāmni mantre sakala-kaluṣa-he śabde-sāmānya buddhir
viṣṇau sarveśvareśe tad-itara-sama-dhīr yasya vā nārakī saḥ
(Padma-purāṇa)
If someone cannot feel the transcendental nature of the Deity, that is not so much of an offence, but if they will not follow to the scriptural injunctions for honouring the Deity, then they must go to hell. Those who worship the Deity do not worship anything material, and the form of the Deity Himself is not material. We must believe this whether we can see it or not. The scriptures instruct us: “You must be conscious about this. You cannot recognise the difference between gold and imitation, but gold is always gold, and you must give honour to that.” From Śrīla Rupa Goswāmī Prabhu in Śrī Bhakti-rasāmṛta-sindhu, Śrīla Jīva Goswāmī Prabhu in Bhakti-sandarbha, and in many other places, we receive this warning: “Don’t forget that you are in the presence of Kṛṣṇa. When you are in front of the Deity, you are in front of Kṛṣṇa Himself, and you must give proper honour to Him.”
Śrīman Mahāprabhu went to the Jagannāth Temple every day to see the form of Lord Jagannāth and always glorified Their Lordships Balabhadra, Subhadra, and Jagannāth. In this way, He set an example for us. When He would stand in front of Jagannāth, He would see Jagannāth as Kṛṣṇa playing flute and attracting the gopīs.
dekhena jagannātha haya muralī-vadana
(Śrī Chaitanya-charitāmṛta: Antya-līlā, 16.85)
Śrīman Mahāprabhu always saw Jagannāth as Kṛṣṇa in this mood. Everything depends on the mood (bhāva) of the devotee.
We must honour the scriptural injunctions about the Deity. For that reason, we are holding a formal devotional function to install the Deity, but the vital point is that the Deity automatically manifests whenever any pure devotee of the Lord pays obeisance. Prabhupād Śrīla Saraswatī Ṭhākur established the service of the Deity in his Temples in this way for his devotees, but some formal installation function is also necessary for the junior, neophyte devotees.
When we offer worship, we follow the processes that are written in the scriptures. But if you put anything in front of a higher devotee, they will immediately think it to be Kṛṣṇa’s prasādam; they will think that Kṛṣṇa has taken it and now it has come to them. This is the feeling of higher standard devotees. We are all very neophyte, junior, and unqualified. We have only soft faith (komala śraddhā), and to make our faith strong, we are holding this function according to the directives of the scriptures.
We are so fortunate that Kṛṣṇa has given us the opportunity to join this festival for the manifestation of the Deity. So, we will honour it properly. Through saṅkīrtan, everything will be fulfilled, and the hearts of the devotees will be filled with joy.
Source
Spoken 18 May 1996.
Reference
archye viṣṇau śilā-dhīr guruṣu nara-matir vaiṣṇave jāti-buddhir
viṣṇor vā vaiṣṇavānāṁ kali-mala-mathane pāda-tīrthe ’mbu-buddhiḥ
śrī-viṣṇor-nāmni-mantre sakala-kaluṣa-he śabda-sāmānya-buddhir
viṣṇau sarveśvareśe tad-itara-sama-dhīr yasya vā nārakī saḥ
(Padma-purāṇa)
“Those who consider the Deity of Viṣṇu to be stone, Śrī Guru to be a man, a Vaiṣṇava to be a member of a particular caste, the wash from the feet of Viṣṇu or the Vaiṣṇava, which destroys the contamination of Kali, to be water, the Name of Viṣṇu and mantras for worshipping Him, which destroy all contamination, to be ordinary words, or Viṣṇu the Lord of all lords to be equal to others are destined for hell.”