The heart of Lord Narasimhadeva is the sankirtana movement.

[Paramananda das]

Srila Prabhupadas has often asked devotees in his lectures and books to please distribute his   books. In  one purport  of the Bhagagavatam Srila Prabhupada has stated it is the duty of every member of ISKCON (SB 7.9.44purport ).

 

The vers reads:   SB 7.9.44: My dear Lord Nṛsiḿhadeva, I see that there are many saintly persons indeed, but they are interested only in their own deliverance. Not caring for the big cities and towns, they go to the Himalayas or the forest to meditate with vows of silence [mauna-vrata]. They are not interested in delivering others. As for me, however, I do not wish to be liberated alone, leaving aside all these poor fools and rascals. I know that without Kṛṣṇa consciousness, without taking shelter of Your lotus feet, one cannot be happy. Therefore I wish to bring them back to shelter at Your lotus feet.

At the end of this purport,Srila Prabhupada writes:

The members of the Kṛṣṇa consciousness movement are not at all interested in so-called meditation in the Himalayas or the forest, where one will only make a show of meditation, nor are they interested in opening many schools for yoga and meditation in the cities. Rather, every member of the Kṛṣṇa consciousness movement is interested in going door to door to try to convince people about the teachings of Bhagavad-gītā As It Is, the teachings of Lord Caitanya. That is the purpose of the Hare Kṛṣṇa movement. The members of the Kṛṣṇa consciousness movement must be fully convinced that without Kṛṣṇa one cannot be happy. Thus the Kṛṣṇa conscious person avoids all kinds of pseudo spiritualists, transcendentalists, meditators, monists, philosophers and philanthropists.

Srila Bhaktisiddhanta Prabhupada in his Upadesavali last instructiones wrote:

Establishing a printing press to print devotional books and preaching by organizing Nama Hatta programs constitutes genuine service to Sri Mayapur.

Lord Narasimha is the protector of the sankirtana movement .In Caitanya Caritamrta  it is recorded of how Chand Kazi tried to stop the sankirtana movement:      CC Ādi 17.175: The Kazi said, "Everyone calls You Gaurahari. Please let me address You by that name.   CC Ādi 17.176: "Kindly listen, O Gaurahari! If You come to a private place, I shall then explain the reason."   CC Ādi 17.177: The Lord replied, "All these men are My confidential associates. You may speak frankly. There is no reason to be afraid of them."   CC Ādi 17.178-179: The Kazi said, "When I went to the Hindu's house, broke the drum and forbade the performance of congregational chanting, in my dreams that very night I saw a greatly fearful lion, roaring very loudly, His body like a human being's and His face like a lion's.   CC Ādi 17.180: "While I was asleep, the lion jumped on my chest, laughing fiercely and gnashing His teeth.   CC Ādi 17.181: "Placing its nails on my chest, the lion said in a grave voice, 'I shall immediately bifurcate your chest as you broke the mṛdańga drum!   CC Ādi 17.182: "'You have forbidden the performance of My congregational chanting. Therefore I must destroy you!' Being very much afraid of Him, I closed my eyes and trembled.   CC Ādi 17.183: "Seeing me so afraid, the lion said, 'I have defeated you just to teach you a lesson, but I must be merciful to you.   CC Ādi 17.184: "'On that day you did not create a very great disturbance. Therefore I have excused you and not taken your life.   CC Ādi 17.185: "'But if you perform such activities again, I shall not be tolerant. At that time I shall kill you, your entire family and all the meat-eaters.'   CC Ādi 17.186: "After saying this, the lion left, but I was very much afraid of Him. Just see the marks of His nails on my heart!"   CC Ādi 17.187: After this description, the Kazi showed his chest. Having heard him and seen the marks, all the people there accepted the wonderful incident.   CC Ādi 17.188: The Kazi continued, "I did not speak to anyone about this incident, but on that very day one of my orderlies came to see me.   CC Ādi 17.189: "After coming to me, the orderly said, 'When I went to stop the congregational chanting, suddenly flames struck my face.   CC Ādi 17.190: "'My beard was burned, and there were blisters on my cheeks.' Every orderly who went gave the same description.   CC Ādi 17.191: "After seeing this, I was very much afraid. I asked them not to stop the congregational chanting but to go sit down at home.

There is another instance in Caitanya Bhagavad where Srivasa Thakura was worshipping Lord Narasimha for protection of from the muslim coming to arrest him due to the loud chanting of Hare Krsna in his house,Lord Caitanya came and forcibly kicked the door in'   ,roaring like a lion :"I am He ,I am HE (Lord Narasimhadeva).

This pastime is mentioned in Caitanya-bhagavata Madhya-khanda, ch. 2, 253-269

" Walking by the riverbank, He (Sri Caitanya Mahaprabhu) saw a herd of cows. They were mooing and drinking water. With raised tails some ran in the four directions. Some fought. Some napped. Some drank water. Seeing them, the Lord began to roar. I am He! I am He!" The Lord shouted again and again. In this way He ran to Srivasa's house.

"Srivasa, what are you doing now?", the Lord roared. Within his home, Srivasa was worshiping Lord Narasimha. Pounding again and again, Sri Caitanya broke the door open. Whom do you worship? On whom do you meditate? Look! The person you worship has come!" the Lord roared.

"Srivasa saw a form like blazing fire, Then his meditation broke. He looked in the four directions. He saw Sri Caitanya sitting in a virasana yoga posture. Sri Caitanya had four arms. He held a conch-shell, cakra, club, and lotus. He roared like a maddened lion. Slapping the palm of His hand against His left shoulder, He made a great sound. Seeing all this, Srivasa trembled. Then he became stunned. He did not move.

"The Lord roared, O Srivasa! For so many days you did not know My true identity? Because of your loud sankirtana I left Vaikuntha and came here with all My associates. Not knowing Me, You left Me and went to Santipura. I will rescue the devotees. I will kill all the demons. Don't worry. Now recite prayers to Me." Gazing at the Lord, Srivasa wept tears of love. The fears in his heart died. Now He was confident. His whole body was filled with joy.

"He offered dandavat obeisances. Then, folding his hands, he recited prayers. By his nature, Srivasa Pandita was a great devotee of the Lord. He accepted the Lord's order. By the Lord's desire, he recited prayers."

Lord Caitanya Himself is Lord Narasimha there is three instances where Lord Caitanya showed this:

CC Ādi 17.90: One day the Lord ordered Śrīvāsa Ṭhākura to read the Bṛhat-sahasra-nāma [the thousand names of Lord Viṣṇu], for He wanted to hear them at that time.   CC Ādi 17.91: As he read the thousand names of the Lord, in due course the holy name of Lord Nṛsiḿha appeared. When Caitanya Mahāprabhu heard the holy name of Lord Nṛsiḿha, He became fully absorbed in thought.   CC Ādi 17.92: In the mood of Lord Nṛsiḿhadeva, Lord Caitanya ran through the city streets, club in hand, ready to kill all the atheists.   CC Ādi 17.93: Seeing Him appearing very fierce in the ecstasy of Lord Nṛsiḿha, people ran from the street and fled here and there, afraid of His anger.   CC Ādi 17.94: Seeing the people so afraid, the Lord came to His external senses and thus returned to the house of Śrīvāsa Ṭhākura and threw away the club.   CC Ādi 17.95: The Lord became morose and said to Śrīvāsa Ṭhākura, "When I adopted the mood of Lord Nṛsiḿhadeva, people were greatly afraid. Therefore I stopped, since causing fear among people is an offense."   CC Ādi 17.96: Śrīvāsa Ṭhākura replied, "Anyone who takes Your holy name vanquishes ten million of his offenses immediately.   CC Ādi 17.97: "There was no offense in Your appearing as Nṛsiḿhadeva. Rather, any man who saw You in that mood was immediately liberated from the bondage of material existence."   CC Ādi 17.98: After saying this, Śrīvāsa Ṭhākura worshiped the Lord, who was then greatly satisfied and returned to His own home.

Lord Narasimhadeva Himself has come from Vaikuntha to hear the Harinama Sankirtana ,and protect the devotees that distribute Srila Prabhupadas books.Lord Vasudeva in Dvaraka has entered the body of Lord Caitanya as He also wanted to experience this ecstatic dancing of love of Godhead(it is mentioned in Gaura Ganodessa Dipika).

Srimad Bhagavatam states:

krsna-varnam tvisa-'krsnam sangopangastra-parsadam   yajnaim sankirtana-prayair-yajanti hi sumedhasam   In the age of Kali, Krsna appears in a golden form, [as Sri Gauranga] chanting the two syllables krsna. He descends along with his weapons [The holy name of Krsna, Srimad-Bhagavatam, kirtana, and mahaprasada ], His limbs [His expansions and avataras such as Nityananda, Advaita, and His divine energies (saktis) such as Gadadhara, Svarupa Damodara, and Ramananda Raya ], and eternal confidential associates [like Srivasa hakura, Haridasa hakura, and other devotees]. Those who are advanced in transcendental intelligence worship Him by performing sankirtana. (Srimad-Bhagavatam 11.5.32)

Lord Caitanya is avatari so with him appears Lord Narasimha

naham tisthami vaikunthe   yoginam hrdayesu va   tatra tisthami narada   yatra gayanti mad-bhaktah “I am not in Vaikuntha nor in the hearts of the yogis. I remain where My devotees engage in glorifying My activities My dear Narada.”

Krsna das Kaviraja has also compared Lord Caitanya to a lion:
  Caitanyera-simhera   nava-dvipe avatara   simha-griva, simha virya   simhera-hunkara   Sei simha vasuk jivera   hrdaya-kandare   kalmasa-dvirada nase   yanhara hunkare   Sri Caitanya-caritamrta Adi-Lila, 3.30-31 (1)   "Thus the lionlike Lord Caitanya has appeared in Navadvipa. He has the shoulders of a lion, the powers of a lion, and the loud voice of a lion. May that lion be seated in the core of the heart of every living being. Thus with His resounding roar may He drive away one's elephantine vices."

Lord Caitanya showed by example the importance to hear the prayers of Prahlada Maharaja in the 7th Canto of Srimad Bhagavatam:

gadadhara parena summukha bhagavata suniya prakase prabhu prema-bhava yata prahlada-caritra, ara dhruvera-caritra sata-vrtti kariya sunena sarhita

"Whenever Sri Gadadhara would recite the Prahlada-caritra and Dhruva-caritra from Bhagavatam, the Lord would manifest various symptoms of love. The Lord would hear the glories of Prahlada and Dhruva hundreds of times." (Sri Caitanya-bhagavata, Antya.10.13-14)

 

Thus ends chapter 15 of Sri Narasimha ,The heart of Lord Narasimhadeva is the sankirtana movement.