That is the process of Caitanya Mahaprabhu's bhajana: feeling of separation, vipralambha, vipralambha-seva. Just like Caitanya Mahaprabhu, feeling the separation of Krsna, He was falling down on the sea. He was coming out of His rest room or His bedroom and going out at dead of night. Nobody knew where He has gone. So that was His searching. This process of devotional service is taught by Caitanya Mahaprabhu. Not that very easily, "We have seen Krsna or seen Radharani in rasa-lila." No, not like that. Feel the separation. The more you feel separation from Krsna, you should understand that you are advancing. Don't try to see Krsna artificially. Be advanced in separation feeling, and then it will be perfect. That is the teachings of Lord Caitanya. Because with our material eyes we cannot see Krsna. Atah sri-krsna-namadi na bhaved grahyam indriyaih [Cc. Madhya 17.136]. With our material senses we cannot see Krsna, we cannot hear about Krsna's name. But sevonmukhe hi jihvadau. When you engage yourself in the service of the Lord… Where the service begins? Jihvadau. The service begins from the tongue. Not from the legs, eyes, or ears. It begins from the tongue. Sevonmukhe hi jihvadau. If you begin service through your tongue… How? Chant Hare Krsna. Use your tongue. Hare Krsna, Hare Krsna, Krsna Krsna, Hare Hare/ Hare Rama, Hare Rama, Rama Rama, Hare Hare. And take Krsna prasadam. The tongue has got two business: to articulate sound, Hare Krsna; and take prasadam. By this process you'll realize Krsna.
>>> Ref. VedaBase => Radhastami, Srimati Radharani's Appearance Day — London, August 29, 1971