Śukadeva Gosvāmī and the wives of the brāhmaṇas who were performing yajña are vivid examples of devotees who achieved the perfectional stage of devotional service by the grace of the Supreme Personality of Godhead.
Eternal Perfection
Persons who have achieved eternal, blissful life exactly on the level of Śrī Kṛṣṇa, and who are able to attract Lord Kṛṣṇa by their transcendental loving service, are called eternally perfect. The technical name is nitya-siddha. There are two classes of living entities—namely, nitya-siddha and nitya-baddha. The distinction is that the nitya-siddhas are eternally Kṛṣṇa conscious without any forgetfulness, whereas the nitya-baddhas, or eternally conditioned souls, are forgetful of their relationship with Kṛṣṇa.
The position of the nitya-siddhas is explained in the Padma Purāṇa in connection with the narration of the Supreme Personality of Godhead and Satyabhāmādevī. The Lord tells Satyabhāmā: "My dear Satyabhāmādevī, I have descended to this earthly planet by the request of Lord Brahmā and other demigods. Those who are born into this family of Yadu are all My eternal associates. My dear wife, you should not consider that My associates are ever separated from Me; they are My personal expansions, and as such, you must know that they are almost as powerful as I am. Because of their transcendental qualities, they are very, very dear to Me, as I am very, very dear to them." Anyone who becomes exhilarated by hearing of the pastimes of Lord Kṛṣṇa when He was present on this earth with His associates is to be understood as nitya-siddha, eternally perfect.
In the Tenth Canto, 14th Chapter, 30th verse, of Śrīmad-Bhāgavatam there is the statement: "How wonderful are the fortunate residents of Vṛndāvana, such as Nanda and the other cowherd men. The Supreme Personality of Godhead, the supreme Brahman, has actually become their intimate friend!"