CC Madhya 8.223
rāga-mārge bhaji’ pāila vrajendra-nandana
“Those saintly persons who represent the Upaniṣads are vivid examples of this. By worshiping the Lord on the path of spontaneous love, they attained the lotus feet of Vrajendra-nandana, the son of Nanda Mahārāja.
In the Goloka Vṛndāvana planet, Kṛṣṇa’s servants are headed by Raktaka and Patraka. Kṛṣṇa’s friends are headed by Śrīdāmā, Subala and others. There are also elderly gopīs and the cowherd men, headed by Nanda Mahārāja, mother Yaśodā and others. All of these personalities are eternally engaged in the loving service of the Lord in accordance with their specific attachments for Kṛṣṇa. One who wants to return home to serve the Lord directly may be attracted to Kṛṣṇa as a servant, friend, father or mother. If a person continuously serves Kṛṣṇa during this life in a particular ecstasy, upon giving up the material body he attains a spiritual body suitable for serving Kṛṣṇa in terms of his particular attachment. One may serve as a servant, friend, father or mother. In the same way, one who wants to serve Kṛṣṇa in conjugal love can attain a body under the guidance of the gopīs. In this connection, the most vivid example is provided by those saintly personalities known as the śrutis, who represent the Upaniṣads. The śrutis understood that without serving Kṛṣṇa and following in the footsteps of the gopīs there would be no possibility of their entering the kingdom of God and serving Kṛṣṇa in the mood of conjugal love. Therefore they engaged in spontaneous loving service unto Kṛṣṇa and followed in the footsteps of the gopīs.