vande śrī-kṛṣṇa-caitanya-nityānandau sahoditau

gauḍodaye puṣpavantaucitrau śan-dau tamo-nudau​

I offer my respectful obeisances unto Śrī Kṛṣṇa Caitanya and Lord Nityānanda, who are like the sun and moon. They have arisen simultaneously on the horizon of Gauḍa to dissipate the darkness of ignorance and thus wonderfully bestow benediction upon all.
(CC Ādi 1.2)

Balarāma appeared with Him as Lord Nityānanda.
(CC Adi 5.6)

Let me offer my obeisances to Lord Śrī Nityānanda, the Supreme Personality of Godhead, whose opulence is wonderful and unlimited. By His will, even a fool can understand His identity.
(CC Adi 5.1)

Although Nityānanda Prabhu is none other than Balarāma Himself, He nonetheless always thinks of Himself as the eternal servant of Lord Śrī Caitanya Mahāprabhu.
(CC Madhya 1.28)

Śrī Nityānanda Prabhu overflooded the entire world by distributing transcendental loving service. No one can understand His character and activities.
(CC Adi 17.297)

The ocean of Lord Nityānanda’s glories is infinite and unfathomable. Only by His mercy can I touch even a drop of it.
(CC Adi 5.157)

Because He is intoxicated by ecstatic love and is an incarnation of mercy, He does not distinguish between the good and the bad. He delivers all those who fall down before Him. Therefore He has delivered such a sinful and fallen person as me.
(CC Adi 5.208-209)

The glories of Lord Nityānanda’s transcendental attributes are unfathomable. Even Lord Śeṣa, with His thousands of mouths, cannot find their limit.
(CC Adi 5.234)

That Lord Nārāyaṇa is a part of a plenary part of Lord Nityānanda Balarāma, who is the source of all incarnations.
(CC Adi 5.107)

Śrīla Nityānanda Prabhu was born in the village of Ekacakrā, in the district of Birbhum, as the son of Padmāvatī and Hāḍāi Paṇḍita. In His childhood He played like Balarāma. When He was growing up, a sannyāsī came to the house of Hāḍāi Paṇḍita and begged to have the paṇḍita’s son as his brahmacārī assistant. Hāḍāi Paṇḍita immediately agreed and delivered his son to him, although the separation was greatly shocking, so much so that Hāḍāi lost his life after the separation.
(CC Adi 17.12 purport)

Within the temple there is a Deity of Śrī Kṛṣṇa established by Śrī Nityānanda Prabhu. The name of the Deity is Baṅkima Rāya or Bāṅkā Rāya. On Baṅkima Rāya’s right side is a deity of Jāhnavā, and on His left side is Śrīmatī Rādhārāṇī. The priests of the temple describe that Lord Nityānanda Prabhu entered within the body of Baṅkima Rāya and that the deity of Jāhnavā-mātā was therefore later placed on the right side of Baṅkima Rāya.
(CC Adi 13.61 purport)

So if we want actually peace of mind, if we actually want to be free from this material fatiguement, then we must take the shelter of Nityānanda Prabhu. Nityānanda Prabhu is the strength, spiritual strength. And without spiritual strength you cannot approach Kṛṣṇa.
(770202 - Lecture Festival Appearance Day - Lord Nityananda Prabhu's Avirbhava - Bhuvanesvara)

In the incarnation of Gaura-Nitāi, the Lord is not supposed to kill demons but is supposed to deliver them by preaching Kṛṣṇa consciousness. In the case of Jagāi and Mādhāi, Śrī Caitanya Mahāprabhu was so angry that He would have immediately killed them, but Nityānanda Prabhu was so kind that He not only saved them from death but elevated them to the transcendental position. Thus what was not possible for Śrī Caitanya Mahāprabhu was carried out by Nityānanda Prabhu.
(CC Madhya 16.65 purport)

If you are actually serious about going back to home, back to Godhead, then please seek after the mercy of Nityānanda
(690131 - Lecture Purport to Nitai-Pada-Kamala - Los Angeles)

Prabhupāda: Nityānanda Prabhu is the spiritual master. Or spiritual master is the replica, representation, of Nityānanda Prabhu. So when Nityānanda Prabhu is pleased, then we become detached from this material attraction.
(740304 - Lecture CC Adi 07.04 - Mayapur)

Śivānanda Sena touched the lotus feet of Nityānanda Prabhu and led Him to His residence. After giving the Lord His quarters, Śivānanda Sena, being very pleased, spoke as follows. Today You have accepted me as Your servant and have properly punished me for my offense. My dear Lord, Your chastising me is Your causeless mercy. Who within the three worlds can understand Your real character? The dust of Your lotus feet is not attainable even by Lord Brahmā, yet Your lotus feet have touched my wretched body. Today my birth, my family and my activities have all become successful. Today I have achieved the fulfillment of religious principles, economic development, satisfaction of the senses and ultimately devotional service to Lord Kṛṣṇa. When Lord Nityānanda heard this, He was very happy. He rose and embraced Śivānanda Sena in great love.
(CC Antya 12.26 - 12.31)

Anyone who wants to cross the material ocean and merge in the ocean of devotional service must worship the lotus feet of Lord Nityānanda.
(Śrī Caitanya-bhāgavata, Adi-khaṇḍa 17.152)

Someone says, “Nityānanda Prabhu is Balarāma,” and another says, “He is the most beloved devotee of Lord Caitanya.” Someone else says, “He is a powerful personality,” and another says, “We don’t understand who He is.” Someone may consider Nityānanda a sannyāsī, someone may consider Him a devotee, and someone may consider Him a jñānī. They may say whatever they like. Even if Nityānanda is a most insignificant servant of Lord Caitanya, I would still keep His lotus feet in my heart. I therefore kick the head of any sinful person who disregards the glories of Lord Nityānanda and dares to criticize Him. All glories to Lord Nityānanda, whose life and soul is Lord Caitanya. Let me take shelter at Your lotus feet.
(Śrī Caitanya-bhāgavata, Adi-khaṇḍa 17.154-159)

Sri Navadvipa Dhama Mahatmya Parikrama Khanda by Srila Bhaktivinoda Thakura is a spiritual guide that leads readers through the divine journey of circumambulating the holy land of Navadvipa. Within his writings, he illuminates the divine journey where Lord Nityananda takes Jiva Gosvami around Navadvipa and shows him the wonderful places of the Lord’s pastimes. It reveals the significance of each sacred site, narrating the glories of Lord Chaitanya’s pastimes, encouraging devotees to undertake this transformative pilgrimage for spiritual enrichment and devotion.
(Sri Navadvipa-Dhama-Mahatmya, Pramana-Khanda, Chapter 1)

Nityānanda means "always." Nitya means "always"; ānanda means "pleasure." This is another meaning you can draw. So therefore, if you have no connection with Nityānanda Prabhu . . . se sambandha nāhi jār bṛthā janma gelo tār: "He's simply wasting time." Bṛthā means "useless." Uselessly, he's wasting time....

So today is Nityānanda Prabhu's appearance day. We shall always pray Nityānanda Prabhu, "Kindly keep me under Your shelter so that . . . I am very duḥkī; I am very unhappy. Under the shelter of Your lotus feet I shall be happy." And that is real happiness. Thank you very much.
(770202 - Lecture Festival Appearance Day - Lord Nityananda Prabhu's Avirbhava - Bhuvanesvara)