One may raise the question how all three worlds became inundated with love of Kṛṣṇa, since Caitanya Mahāprabhu performed kīrtana only in the Navadvīpa area. The answer is that Lord Śrī Caitanya Mahāprabhu is Kṛṣṇa Himself. The entire cosmic manifestation results from the Lord's first setting it in motion. Similarly, since the saṅkīrtana movement was first set in motion five hundred years ago by Śrī Caitanya Mahāprabhu's desire that it spread all over the universe, the Kṛṣṇa consciousness movement, in continuity of that same motion, is now spreading all over the world, and in this way it will gradually spread all over the universe. With the spread of the Kṛṣṇa consciousness movement, everyone will merge in an ocean of love of Kṛṣṇa.
(Sri Caitanya Caritamrta------1;13:32------purport).

Lord Nityānanda Prabhu, the avadhūta, is also directly the Supreme Personality of Godhead. He is always intoxicated with the madness of ecstatic love. Indeed, He is an ocean of love of Kṛṣṇa.
(Sri Caitanya Caritamrta------3:7:20------translation).

The ocean of ecstatic love for Kṛṣṇa is very difficult to understand, even for such demigods as Lord Brahmā. By enacting His pastimes, Śrī Caitanya Mahāprabhu submerged Himself in that ocean, and His heart was absorbed in that love. Thus He exhibited in various ways the exalted position of transcendental love for Kṛṣṇa.
(Sri Caitanya Caritamrta------3:15:1------translation).

One queen addressed a swan as follows: “My dear swan, please come here, come here. You are welcome. Please sit down and take some milk. My dear swan, can you tell me if you have any message from Śyāmasundara? I take you to be a messenger from Him. If you have any such news, please tell me. Our Śyāmasundara is always very independent. He never comes under the control of anyone. We have all failed to control Him, and therefore we ask you, Is He keeping Himself well? I may inform you that Śyāmasundara is very fickle. His friendship is always temporary; it breaks even by slight agitation. But would you kindly explain why He is so unkind to me? Formerly He said that I alone am His dearmost wife. Does He remember this assurance? Anyway, you are welcome. Please sit down. But I cannot accept your entreaty to go to Śyāmasundara. When He does not care for me, why should I be mad after Him? I am very sorry to let you know that you have become the messenger of a poor-hearted soul. You are asking me to go to Him, but I am not going. What is that? You talk of His coming to me? Does He desire to come here to fulfill my long expectation for Him? All right. You may bring Him here. But don't bring with Him His most beloved goddess of fortune. Do you think that He cannot be separated from the goddess of fortune even for a moment? Could He not come here alone, without Lakṣmī? His behavior is very displeasing. Does it mean that without Lakṣmī, Śyāmasundara cannot be happy? Can't He be happy with any other wife? Does it mean that the goddess of fortune has the ocean of love for Him and none of us can compare to her?”
(Krsna Book).