CC Madhya 6.184

prabhu kahe, — bhaṭṭācārya, nā kara vismaya
bhagavāne bhakti — parama-puruṣārtha haya
Synonyms: 
prabhu kahe — the Lord said; bhaṭṭācārya — My dear Bhaṭṭācārya; — not; kara — do; vismaya — astonishment; bhagavāne — unto the Supreme Personality of Godhead; bhakti — devotional service; parama — the supreme; puruṣa-artha — human interest; haya — is.
Translation: 
Lord Śrī Caitanya Mahāprabhu then told him, “Do not be astonished. Actually, devotional service unto the Supreme Personality of Godhead is the highest perfection of human activity.