Being a pure devotee
Bhagavad-gita As It Is
BG Chapters 7 - 12
But one cannot be divine without being a pure devotee of Kṛṣṇa
BG 11.48, Purport: The Bhagavad-gītā gives the description of the universal form. Although this description was unknown to everyone before Arjuna, now one can have some idea of the viśva-rūpa after this incident. Those who are actually divine can see the universal form of the Lord. But one cannot be divine without being a pure devotee of Kṛṣṇa.
SB Canto 1
The inhabitants of Dvārakā, can see Him face to face by the grace of the Lord.
SB 1.11.8, Purport: Neither Brahmājī nor the demigods like Indra can enter into this island of Śvetadvīpa, but they can stand on the shore of the ocean of milk and transmit their message to Lord Viṣṇu, known as Kṣīrodakaśāyī Viṣṇu. Therefore, the Lord is rarely seen by them, but the inhabitants of Dvārakā, because of their being pure devotees without any tinge of the material contamination of fruitive activities and empiric philosophical speculation, can see Him face to face by the grace of the Lord.
The child in the womb of his mother was spotless due to his being a pure devotee of the Lord
SB 1.12.16, Purport: The child Parīkṣit was saved by the all-powerful and all-pervasive Viṣṇu (Lord Kṛṣṇa) for two reasons. The first reason is that the child in the womb of his mother was spotless due to his being a pure devotee of the Lord. The second reason is that the child was the only surviving male descendant of Puru, the pious forefather of the virtuous King Yudhiṣṭhira.
SB Canto 2
Arjuna, who was a bona fide candidate for understanding due to his being a pure devotee of the Lord
SB 2.2.27, Purport: But in due course of time the authorized succession was broken, and therefore, just to reestablish the true spirit of the knowledge, the Lord again explained the same knowledge to Arjuna, who was a bona fide candidate for understanding due to his being a pure devotee of the Lord.
But being a pure devotee, Arjuna agreed to fight on the instruction of the Lord
SB 2.3.10, Purport: Even without so-called liberation, a pure devotee is aspirant for the satisfaction of the Lord. Influenced by the kāma spirit, Arjuna declined to fight in the Kurukṣetra battlefield because he wanted to save his relatives for his own satisfaction. But being a pure devotee, he agreed to fight on the instruction of the Lord because he came to his senses and realized that satisfaction of the Lord at the cost of his own satisfaction was his prime duty. Thus he became akāma. That is the perfect stage of a perfect living being.
The elephant, being a pure devotee of the Lord, specifically deserved to be saved from the attack of the crocodile
SB 2.7.15, Purport: The elephant addressed the Lord as akhila-loka-nātha, or the Lord of the universe, who is therefore the Lord of the elephant also. The elephant, being a pure devotee of the Lord, specifically deserved to be saved from the attack of the crocodile, and because it is a promise of the Lord that His devotee will never be vanquished, it was quite befitting that the elephant called upon the Lord to protect him, and the merciful Lord also at once responded.
SB Canto 7
SB 7.13.22, Translation: Nārāyaṇa, the Supreme Personality of Godhead, who is full of all opulences, is predominant within the core of your heart because of your being a pure devotee. He always drives away all the darkness of ignorance, as the sun drives away the darkness of the universe.
It is a fact that no one can see Krsna without being a pure devotee of the Lord
Letter to Gerald — ISKCON: Akash Ganga Bldg; 89 Bhulabhai Desai Road; Bombay-26 India 19th February, 1971: Yes, it is a fact that no one can see Krsna without being a pure devotee of the Lord. Every living entity is the son of god, but not all of the sons are faithful to their Father. This is explained in Bhagavad Gita. So one who turns away from his father naturally cannot see his father; but the faithful son can see his father at any time. Under the circumstances, we can understand the word of John because amongst all the people of that place Jesus Christ was the only faithful son of God, Krsna.