While Romans had always had major State festivals to gods like Jupiter and Mars, nearer and dearer to most Roman families were a simple household based religion based around local and familial spirits. These local and familial demons were the mainstay of Roman religion throughout all stages of its history, from archaic origins to the Christian era. The worship of these spirits is what truly defines Roman religion, and what really separates it from the sister religion of Greek paganism.
Within the privacy of their homes each Roman family honored its ancestors and tutelary demons according to its own understandings. The venerable paterfamilias was very much the high priest of his own household religion; he honored his fathers and the gods of his fathers, and it was expected that his sons would honor his spirit and his gods when the time came. The paterfamilias held the power of life and death over his family and his servants. While this became increasingly theoretical with the evolution of Roman society, it was rooted in the religious taboo that the father was the link between the family and its tutelary gods and ghosts.
Indeed, it was not so much the paterfamilias who was owner of the house, it was his deified ancestors and local spirits who were the real proprietors and guardians of the land. The family demons could bring woe to those who offended them, and surely there was no greater insult than to lay a hand upon the paterfamilias whose chief duty was to propitiate them. Outsiders were also thought to invite divine wrath if they attempted to evict or harm a man within the presence of his household familiars. These religious taboos rendered domestic life and private property sacred centuries before civil law was accepted as a substitute.
The residence of a paterfamilias was virtually a temple to the family gods, and it therefore followed the house was itself sacred in some sense. The hearth which cooked the family's food and kept them from freezing in the cold was Vesta. Vesta like her Greek counterpart Hestia seems to be a very ancient Indo-European goddess of domestic fire. The women of the house were charged with maintaining Vesta's flames, and to let the flames extinguish was a disgrace. Small bits of the family's evening meal would be offered to Vesta's flames as an offering. The revered temple of Vesta with its cult of Virgins was a public outgrowth of this private cult.
The household door, the veil between the inner sanctity of family life and the profanity of the outside world, was also sacred. Janus was its name, and seems to have been a very ancient Italian deity connected with beginnings and transitions. The sons of the paterfamilias were charged with the worship of Janus, though not much is known about this. Even parts of the door were considered sacred: Forculus presided over the panels, and Cardea over the hinges. Limentinus was the threshold. The Greeks felt the Romans were a bit anal to find gods in so many small things, and later Christians made much mockery of these petty gods. But to the Roman, no god was so meaningful and so self-evident as the gods of the house, small though they were.
The paterfamilias took delight in having the household honor his genius. The genius was a kind of spiritual double, often portrayed as either a snake or a stately male in a toga and covered head. Somehow connected with the family line, the genius imbued the individual with procreative and inspirational powers. The genius was a kind of tether to the family line which, through the act of procreation, a paterfamilias was able to pass to the next generation. Every male had a genius, and every woman had a similar double called a juno (not to be confused with the deity of the same name) but the genius of the paterfamilias was central to the family cult and honored on his birthday. The Romans seemed to feel that because of the influence of a genius, an individual's character was written at birth which experience and education could only moderate.
Beginning with Augustus, the emperors would say that as the paterfamilias of the Roman race, their own genius was worthy of public veneration. This is what constituted the imperial ruler cult in the West, and over which early Christians had so much controversy. In the Roman understanding the emperor was not a god while alive, but as head of the public family his genius (spiritual essence) was worthy of rites. Most Christians did not seem to care about the distinction and regarded the honoring of the imperial genius as tantamount to worshipping a god, an offense to their religion.
The Greek conception of the afterlife - the shadowy abode of Hades - was a poetic conceit adopted by some of the Roman literati. However, Roman religion per se did not recognize a specific dwelling place for the souls of the dead. The souls of the dead were deified in an aggregated sense and referred to as the Manes. The Manes held power over the living and were a part of the world, the real owners of the land.
The Manes were divided into two sects. The Lares were spirits that were helpful, so long as they were propitiated. Every family was thought to have its own tutelary Lar, called the Lar Familiaris, who was honored by the paterfamilias. The Lares were originally honored outside on the borders between farming properties. Later, as Rome lost its agricultural character, the Lares came inside and were honored in a special shrine called the Lararium. There were still more "public" Lares who were honored at the crossroads in the neighborhood wards of Rome; Augustus set up special colleges for this. In any case the Lares were souls of the dead (ancestors) who guarded a family or piece of land. There were especially honored on the Kalends, Nones, and Ides of the calendar. The usual offerings were scraps of food or incense burned in their honor.
The Lares were also known as the genii loci - the spirits of the land. They were thought to particularly inhabit natural settings like springs and forest groves. Whenever the Romans cleared land for some earthwork project, they first made sacrifices to the genii loci. This does not mean that Romans were reluctant to clear the land, merely that they felt the spirits within first deserved a sacrifice to avert their wrath.
The Manes also had a malignant sect, an evil version of the Lares, called either Lemures or Larvae. The Lemures were thought to be souls of the discontented who caused mischief and harm. There were throughout the course of the year several festivals (some rather bizarre in nature) designed to scare aware the Lemures and avert their wrath.
Also of vital importance to a family were the Penates, the gods of the penus or store pantry. These were the major gods most directly concerned with the family's well-being, and usually had some relation to the profession or interests of the paterfamilias. For instance, Minerva was the patron of craftsmen, so a craftsmen would most likely honor Minerva as one of his Penates. Mercury was the patron of merchants, thus a merchant would be inclined to honor Mercury as a penates god. It seemed every Roman family had from two to eight patron or Penates gods, which they represented either by crude figurines or else by drawing their likeness somewhere on a familial shrine. It was said the Penates particularly delighted in the smell of food and roasted meat.
Every family belonged to a clan, and these clans themselves had special patron gods and corresponding rites. The Julian clan honored Venus and Apollo. The Nero clan, Bellona the war goddess. The Aurelians honored the sun. The Claudians honored Hercules. The leading families of these clans were responsible for maintaining the shrines and rites for the rest of the clan. When one of these clans came to power they had a habit of enshrining their private gods in the State conscious by building public temples and/or issuing coinage with the likeness of the relevant deities.
Beyond gods and spirits, there were religious rights to accompany an individual from birth to death. Men often kept the first trimmings of their beard in a box on the family shrine. When a young man became of age, he traded in his child's toga for an adult toga, and then went to the temple of Jupiter to offer sacrifice. Families kept wax funeral masks of their dead in their house. When a woman married, she formally left the protection of her father and his household gods and entered into the protection of her husband and his household gods.
This was the simple religion of the Romans that endured for centuries. Only the death penalty from the new Christian government formally ended it.
Turcan, Robert. _The Gods of Ancient Rome
Scheid, John. _An Introduction to Roman Religion
Adkins and Adkins. _Dictionary of Roman Religion
Hornblower and Spawforth. _Oxford Classical Dictionary
This article was provided by forum member Ursus