Srila Prabhupada herein vividly and beautifully elucidates the highest form and object of concentration that one's mind can meditate on—the beautiful form of the supreme Lord.
It is by great fortune that one comes to Krsna consciousness on the path of bhakti-yoga to become well situated according to the Vedic direction. The ideal yogi concentrates his attention on Krsna who is called Syamasundara, who is as beautifully colored as a cloud, whose lotuslike face is as effulgent as the sun, whose dress is brilliant with jewels and whose body is flower-garlanded. Illuminating all sides is His gorgeous luster, which is called the brahma-jyoti. He incarnates in different forms such as Rama, Nrsimha, Varaha and Krsna, the Supreme Personality of Godhead, and He descends like a human being, as the son of mother Yasoda, and He is known as Krsna, Govinda and Vasudeva. He is the perfect child, husband, friend and master, and He is full with all opulences and transcendental qualities. If one remains fully conscious of these features of the Lord, he is called the highest yogi.
The impersonalists can imagine or even perceive that the Supreme Brahman is thus all-pervading, and therefore they conclude that there is no possibility of His personal form. Herein lies the mystery of transcendental knowledge of the Personality of Godhead. This mystery is transcendental love of Godhead, and one who is surcharged with such transcendental love of Godhead can without difficulty see the Personality of Godhead in every atom and every movable or immovable object. And at the same time he can see the Personality of Godhead in His own abode, Goloka, enjoying eternal pastimes with His eternal associates, who are also expansions of His transcendental existence. This vision is the real mystery of spiritual knowledge, as stated by the Lord in the beginning of His instructions to Brahmaji (sarahasyam tad-angam ca). This mystery is the most confidential part of the knowledge of the Supreme, and it is impossible for the mental speculators to discover it by dint of intellectual gymnastics. The mystery can be revealed through the process recommended by Brahmaji in his Brahma-samhita (5.38) as follows:
santah sadaiva hrdayesu vilokayanti
yam syamasundaram acintya-guna-svarupam
govindam adi-purusam tam aham bhajami
"I worship the original Personality of Godhead, Govinda, whom the pure devotees, their eyes smeared with the ointment of love of Godhead, always observe within their hearts. This Govinda, the original Personality of Godhead, is Syamasundara with all transcendental qualities."
Therefore, although He is present in every atom, the Supreme Personality of Godhead may not be visible to the dry speculators; still the mystery is unfolded before the eyes of the pure devotees because their eyes are anointed with love of Godhead. And this love of Godhead can be attained only by the practice of transcendental loving service of the Lord, and nothing else. The vision of the devotees is not ordinary; it is purified by the process of devotional service. In other words, as the universal elements are both within and without, similarly the Lord's name, form, qualities, pastimes, entourage, etc., as they are described in the revealed scriptures or as performed in the Vaikunthalokas, far, far beyond the material cosmic manifestation, are factually being televised in the heart of the devotee. The man with a poor fund of knowledge cannot understand, although by material science one can see things far away by means of television. Factually, the spiritually developed person is able to have the television of the kingdom of God always reflected within his heart. That is the mystery of knowledge of the Personality of Godhead.
When Lord Sri Krsna was personally present in the mortal world in His eternal, blissful form of Syamasundara, those who were not pure devotees of the Lord could not recognize Him or know His glories. Avajananti mam mudha manusim tanum asritam (Bg. 9.11): He is always bewildering to the nondevotees, but He is always seen by the devotees by dint of their pure devotional service to Him.
>>> Ref. VedaBase => SB 3.1.43