Persons who are peaceful, equipoised, cleansed and purified, and who know the art of pleasing all other living entities, keep friendship only with devotees of the Lord; they alone can very easily achieve the perfection of going back home, back to Godhead.
The description of this verse fully indicates that only devotees are eligible to enter into the kingdom of Godhead. The first point stated is that devotees are peaceful, for they have no demands for their personal sense gratification. They are simply dedicated to the service of the Lord. Karmīs cannot be peaceful because they have immense demands for sense gratification. As for jñānīs, they cannot be peaceful because they are too busy trying to attain liberation or merge into the existence of the Supreme. Similarly, yogīs are also restless to get mystic power. But a devotee is peaceful because he is fully surrendered to the Supreme Personality of Godhead and thinks of himself as completely helpless; just as a child feels complete peace in depending on the parent, so a devotee is completely peaceful, for he depends on the mercy of the Supreme Personality of Godhead.
A devotee is equipoised. He sees everyone on the same transcendental platform. A devotee knows that although a conditioned soul has a particular type of body according to his past fruitive activities, factually everyone is part of the Supreme Lord. A devotee sees all living entities with spiritual vision and does not discriminate on the platform of the bodily concept of life. Such qualities develop only in the association of devotees. Without the association of devotees, one cannot advance in Kṛṣṇa consciousness. Therefore, we have established the International Society for Krishna Consciousness. Factually, whoever lives in this society automatically develops Kṛṣṇa consciousness. Devotees are dear to the Supreme Personality of Godhead, and the Supreme Personality of Godhead is only dear to devotees. On this platform only can one make progress in Kṛṣṇa consciousness. Persons in Kṛṣṇa consciousness, or devotees of the Lord, can please everyone, as is evident in the Kṛṣṇa consciousness movement. We invite everyone, without discrimination; we request everyone to sit down and chant the Hare Kṛṣṇa mantra and take as much prasāda as we can supply, and thus everyone is pleased with us. This is the qualification. Sarva-bhūtānurañjanāḥ. As for purification, no one can be more pure than devotees. Anyone who once utters the name of Viṣṇu immediately becomes purified, inside and outside (yaḥ smaret puṇḍarīkākṣam). Since a devotee constantly chants the Hare Kṛṣṇa mantra, no contamination of the material world can touch him. He is, therefore, actually purified. Muci haya śuci haya yadi kṛṣṇa bhaje. It is said that even a cobbler or person born in the family of a cobbler can be elevated to the position of a brāhmaṇa (śuci) if he takes to Kṛṣṇa consciousness. Any person who is purely Kṛṣṇa conscious and who engages in chanting the Hare Kṛṣṇa mantra is the purest in the whole universe.
[Srimad Bhagavatam 4.12.37]