The most characteristic aspect of the traditional Roman religion is the household or family cult of the Dii Familiares. In this cult, the Lar Familiaris (guardian spirit - Genius - of the family), the Lares Loci (guardian spirits of the place where the house is built), the Genius of the pater familias (house-father), the Dii Penates (patron gods of the storeroom), the Dii Manes (spirits of the deceased) and a multitude of other domestic deities are daily worshipped by the members of the family. The household cult is so important that it even serves as the model for several practices of the state cult (e.g. there were the Lares Praestites, Penates Publici) Even during the Empire, the imperial cult came to be based on the household cult, now interpreted as the cult of the Genius of the emperor, pater familias of the family of all the Romans).
The Lar Familiaris is the guardian spirit of a family and symbolizes the household. He was honored on all family occasions: a new brideoffered a coin and a sacrifice on entering her new house. Rams are sacrificed to the Lar Familiaris after funerals as a purification rite. During the 1st century AD, the Romans came to honor two Lares instead of one, becoming strongly connected with the Penates. In the lararium, the Lares are usually represented in dancing poses, carrying greek rhytones of wine.
The Lares Loci are the guardian spirits of a place. In the lararium, the Lares Loci of the place where the house is built are also honoured, being represented by one or more serpents.
Each man has a Genius, each woman a Iuno. This is the creative force that engenders the individual and imbues him/her with growth, learning and morality. This spirit stays with the person until death. The Genius of the paterfamilias deserves special honor, and is represented in the lararium by a man dressed in white with the head covered by the toga.
The Penates are connected with each family. If the family moves, the Penates go with it. They are the spirits of the larder, of food and drink, and they share the hearth as an altar with the Goddess Vesta.
The Manes are the spirits of the dead ancestors. When the deceased receives the due honours and rites, he is allowed to ascend from the Underworld to protect his family. This is in contrast with the Lemures or Larvae, evil ghosts which are the souls of the dead who the Dii Inferi refused to receive in the Underworld.
Each corner of the house is under the influence of a protector God. Forculus protects the door, Limentinus the threshold, Cardea the hinges. Vesta protects the hearth. Each tool has also its protector spirit: Deverra protects the broom, Pilumnus the rammer, Intercidona the axe.
The generation of a human being is also ruled by protector Gods. Iuno and Mena assure the menstrual flux of the future mother. Jugatinus presides to the union of man and woman. Cinxia or Virginensis uncover the woman's girdle. Subigus delivers her to the man. Prema commands the penetration. Inuus (Tutunus or Mutunus) and Pertunda put an end to virginity. Ianus, God of passage, opens the way for the generating seed emanated from Saturnus, but it is Liber who allows the ejaculation. Once concepted, the new human being needs Fluonia or Fluvionia, Who retains the nourishing blood. But the nourishing itself is presided by Alemona. To avoid the dangers of upside-down pregnancy, Postverta and Prosa are invoked. Diana Nemorensis is also invoked to allow a good pregnancy. Three dities protect the mother from the violence of Silvanus: Intercidona, Deverra and Pilumnus. In the the atrium, a bet is setup for Pilumnus and Picumnus or Iuno, and a table is setup for Hercules. Nona and Decima allow the birth between the ninth and tenth month. But it is Egeria who makes the baby come out (egerere). Parca or Partula preside to the birth, but it is Vitumnus Who gives life, Sentinus the senses. After the birth, Lucina, bringer of light, must be invoked. Lucina is also the Goddess to whom sterile (or with pregnancy desease) women direct their prayer. After the birth, the pregnant women must be purified, and it is Iuno Februa (Februalis or Februlis) Who frees them from the placental membrane. With the aid of Levana, the sage-woman raises and presents the child to the mother. The father then raises the child with the aid of Statina (Statilina, Statinus or Statilinus).