“Shraddha is a ritualistic performance observed by the followers of the Vedas. There is a yearly occasion of fifteen days when ritualistic religionists follow the principle of offering oblations to departed souls. Thus those fathers and ancestors who, by freaks of nature, might not have a gross body for material enjoyment can again gain such bodies due to the offering of shraddha oblations by their descendants. The performance of Shraddha, or offering oblations with Prasada, is still current in India, especially at Gaya, where oblations are offered at the lotus feet of Viṣṇu in a celebrated temple. Because the Lord is thus pleased with the devotional service of the descendants, by His grace He liberates the condemned souls of forefathers who do not have gross bodies, and He favors them to again receive a gross body for development of spiritual advancement.
Unfortunately, by the influence of Maya, the conditioned soul employs the body he gets for sense gratification, forgetting that such occupation may lead him to return to an invisible body. The devotee of the Lord, or one who is in Krishna consciousness, however, does not need to perform such ritualistic ceremonies as shraddha because he is always pleasing the Supreme Lord; therefore his fathers and ancestors who might have been in difficulty are automatically relieved. The vivid example is Prahlada Maharaja. Prahlada Maharaja requested Lord Nrsimhadeva to deliver his sinful father, who had so many times offended the lotus feet of the Lord. The Lord replied that in a family where a Vaisnava like Prahlada is born, not only his father but his father’s father and their fathers–up to the fourteenth father back–are all automatically delivered. The conclusion, therefore, is that Krishna consciousness is the sum total of all good work for the family, for society and for all living entities. In the Caitanya-caritamrta the author says that a person fully conversant with Krishna consciousness does not perform any rituals because he knows that simply by serving Krishna in full Krishna consciousness, all rituals are automatically performed.
Source: A.C. Bhaktivedanta Swami Prabhupada (2014 edition), “Srimad Bhagavatam”, Third Canto, Chapter 20 – Text 43