once krishna said

Vyādha Gītā chapter 6 indriyāṇyeva tat sarvaṁ yat svarga narakāvubhau | nigṛhīta visṛṣṭāni svargāya narakāya ca || 18 || The concept of heaven and hell are both dependent on our senses, when one is in control of one's senses then svarga (heaven) is said to exist, lack of control is naraka (hell). Vasishta Itihāsa purāṇābhyām vedam sam-upabṛmhayet | Bibhetyalpa śrutād vedo mām ayam prahariṣyati || The Veda is to be interpreted through means of the Itihāsas and Purāṇas. The Veda dreads a person of little learning fearing — “he will misunderstand me!” (Vasiṣṭha Dharma sūtra 27:6) Vaikuntha... Reality Attainment of Vaikuṇṭha is mentioned in Nārāyaṇā Upaṇiṣad:– pratyag ānandaṃ brahma puruṣaṃ praṇa̍va svarū̱paṃ | akāra ukāra makā̍ra i̱ti | tān ekadhā samabharat tad eta̍d oṃ i̱ti | yam uktvā̍ mucya̍te yo̱gī̱ ja̱nma̱ saṃsā̍ra ba̱ndhanāt | oṃ namo nārāyaṇāyeti ma̍ntropā̱sakaḥ | vaikuṇṭha bhavana loka̍ṃ gami̱ṣyati | t || 4 || The Yogi that recites the name of Him who is Bliss Abs

source : mahabharata ( sabha parva.ch V ) we already know who narada is and what was his job but little we know anything about his accomplishments and siddhis . It is been mentioned in the mahabharata Vaisampayana-said, ''While the illustrious Pandavas were seated in that Sabha  along with the principal Qandharvas, there came, O Bharata, unto that assembly  the celestial Rishi Narada,  conversant with the Vedas and Upanishadas, worshipped by the celestials acquainted with histories and Puranas, well-versed in all that occured in ancient kalpas (cyles), conversant with  Nyaya (logic) and the truth of moral science, possessing a complete knowledge of the six Angas  (viz., pronunciation, grammar, prosody, explanation of basic terms, description of religious rites, and astronomy and astrology).  He was a perfect master in reconciling contradictory texts and differentiating in  applying general principles to particular cases, as also in interpreting contraries by reference to differ

For the sake of yagna if the animal is been sacrificed its considered okay by the shastras . here are some references Verses for sacrifice of animal and eating atrāpi vidhir uktaś ca munibhir māṁsa-bhakṣaṇe | devatānāṁ pitṛṇāṁ ca bhuṅkte dattvā tu yaḥ sadā | yathā vidhi yathā śraddhaṁ na sa duṣyati bhakṣaṇāt || 12 || And in this matter of animal food, this rule has been laid down by Munis:– Whoever partakes of animal food after having first offered it duly and respectfully to the gods and the manes, is not polluted by the act.(vyadha gita adhyayA 2) Commentary Manu 5:40 - 43. Herbs, trees, cattle, birds, and (other) animals that have been destroyed for sacrifices, receive (being reborn) higher existences. On offering the honey-mixture – madhu-parka (to a guest), at a sacrifice and at the rites in honour of the Ancestors, but on these occasions only, may an animal be slain; that (rule) Manu has proclaimed. A twiceborn man who, knowing the true meaning of the Veda, slays an animal for th