"In the Amarakosa Sanskrit dictionary the word murti carries import in twofold meanings, namely, form and difficulty. Therefore amurtikam is explained by Acarya Sri Visvanatha Cakravarti Thakura as meaning "without difficulty." The transcendental form of eternal bliss and knowledge can be experienced by our original spiritual senses, which can be revived by chanting of the holy mantras, or transcendental sound representations. Such sound should be received from the transparent agency of the bona fide spiritual master, and the chanting may be practiced by the direction of the spiritual master. That will gradually lead us nearer to the Lord. This method of worship is recommended in the pancaratrika system, which is both recognized and authorized. The pancaratrika system has the most authorized codes for transcendental devotional service. Without the help of such codes, one cannot approach the Lord, certainly not by dry philosophical speculation. The pancaratrika system is both practical and suitable for this age of quarrel. The Pancaratra is more important than the Vedanta for this modern age."
Srimad-Bhagavatam 1:5:38 Purport
"The scriptures known as the Pancaratra-sastras are recognized Vedic scriptures that have been accepted by the great acaryas. These scriptures are not products of the modes of passion and ignorance. Learned scholars and brahmanas therefore always refer to them as satvata-samhitas. The original speaker of these scriptures is Narayana, the Supreme Personality of Godhead. This is especially mentioned in the Moksa-dharma (349.68), which is part of the Santi-parva of the Mahabharata. Liberated sages like Narada and Vyasa, who are free from the four defects of conditioned souls, are the propagators of these scriptures. Sri Narada Muni is the original speaker of the Pancaratra-sastra"
Caitanya-caritamrta, Adi lila 5:41
There are 108 Pancaratra books describing the system of worship of the Lord in His Deity form, as explained by great authorities on devotional service like Lord Brahma, Lord Siva, Laksmidevi, and others. Among the most prominent of the Pancaratra are the Padma Pancharatra, Narada Pancharatra, Hayasirsa Pancharatra, Laksmi-tantra, and Mahesa Pancharatra. These books provide elaborate descriptions of the Lord's expansions and incarnations, particularly the Deity forms. It provides instruction for temple worship, including the Deity forms, methods of purification, processes for installing Deities, conducting different levels of worship and different festival events, and various paraphernalia required for such worship.
Acaryas in each of the Vaisnava sampradayas have compiled their unique versions of Pancaratra manuals. In the Gaudiya Vaisnava sampradaya, Lord Caitanya Mahaprabhu instructed Rupa Goswami and Sanatana Goswami on these teachings, and directed them to write books on the matter. Sanatana Goswami provided Hari bhakti-vilas, and Srila Rupa Goswami provided the Bhakti rasamrta-sindhu, which Srila Prabhupada purported in his Nectar of Devotion.
Bhaktivedanta Book Trust. HDG A.C. Bhaktivedanta Swami Srila Prabhupada.