Our real identity is eternal servant of Kṛṣṇa: jīvera svarūpa haya nitya-kṛṣṇa-dāsa (CC Madhya 20.108-109). So we want to keep that identity, and we want to serve Him eternally. Eternally means now we are in this material world, we are being trained up how to serve Kṛṣṇa. This Deity worship, this is a training. The same thing will continue when you go to Vaikuṇṭha or Vṛndāvana. The same way we shall personally serve. Here, Kṛṣṇa . . . this is also personally. But due to my imperfectness, I cannot see Kṛṣṇa in His actual spiritual form, sac-cid-ānanda-vigraha (Bs. 5.1). Therefore Kṛṣṇa has assumed a form which you can approach. It is for your facility. And Kṛṣṇa, in any form He appears, He is transcendental, either this form or that form. Nāma cintāmaṇiḥ kṛṣṇaś caitanya-rasa-vigrahaḥ (CC Madhya 17.133). Everything.
That is Kṛṣṇa's speciality. He can appear . . . just like if you have got a photograph of some of your friend, so you cannot derive the benefit of directly meeting him. But in Kṛṣṇa's form, if you have a Kṛṣṇa's photograph, it is as good as Kṛṣṇa. That is the difference. You can get the same benefit from the photograph picture of Kṛṣṇa as you get benefit by directly meeting Him. Therefore, meeting this photograph, Deity of Kṛṣṇa, is as good as Kṛṣṇa.