CC Ādi 5.229

yāṅra prāṇa-dhana — nityānanda-śrī-caitanya
rādhā-kṛṣṇa-bhakti vine nāhi jāne anya
Word for word: 
yāṅra — whose; prāṇa-dhana — life and soul; nityānanda-śrī-caitanya — Lord Nityānanda and Śrī Caitanya Mahāprabhu; rādhā-kṛṣṇa — to Kṛṣṇa and Rādhārāṇī; bhakti — devotional service; vine — except; nāhi jāne anya — do not know anything else.
Translation: 
Lord Caitanya and Lord Nityānanda are the life and soul of those Vaiṣṇavas, who do not know anything but devotional service to Śrī Śrī Rādhā-Kṛṣṇa.