There are no documents that really give us a lot of information about early religious developments, but there are lots of survivals of the earlier religion of the Romans in later Roman religious activities. It is hard for modern students to understand Roman religion because their assumptions about religion, its purposes and activities are so different from ours. Roman religion did not perform the same functions that modern religion does. For Romans, religion was not a vehicle for discovering the truth of nature, or for gaining an understanding of god or man. Romans left no teachings or religious doctrines in modern sense.

Romans’ beliefs and practices were a part of the traditional Roman way of life. Their cults and deities belonged to them and to no one else, so Romans not concerned with other people’s religion, nor were they concerned with converting other peoples to their religion. Roman religion provided no moral codes, no important life lessons, and little or no spiritually uplifting messages. Morality was enforced by social convention rather than by religious influence.

Most important rules had to do with the performance of appropriate and correct ritual. Romans, thus, did not believe that there were rewards or punishments after death. If they believed that souls survived at all they thought that the soul stayed in the grave with the body. All rewards and punishments were in this life. If gods liked you, you would have good fortune. If the gods didn’t you would have bad fortune, and would fail in your undertakings. Roman religion was designed to maintain what Romans called the pax deorum – a state of peace between men and the gods. It was meant to encourage a favorable attitude of the gods towards individuals, families and the Roman people. Anything that you wanted to do required the support of the gods. The chief purpose of religion, then. was to ensure success through help of gods. It was necessary to insure that the gods would be friendly and to make sure that the gods will continue to be friendly in the future.

The Romans engaged in several kinds of religious observances. In practice all combined together from time to time. Auspicia involved divination, either active or passive. The gods freely gave signs of the future all the time. Some ordinary occurrences were considered auspicious, so Romans examined nature in order to see the intent of the gods in natural occurrences. They might observe the flight of birds to see what direction that they flew in. They would observe odd happenings like storms, or cloud formations, the birth of deformed animals, the specific behavior of animals (especially those associated with particular deities).

Officials or pater familiae examined the entrails of sacrificial animals, or even animals that had been killed for meals. These were just a few ways that  Romans searched for omens. Another important activity was called Sacrificium (sacrifice). Whereas the taking of the auspices could be said to be a passive activity (searching for the intent of the gods), sacrifice was a active. Romans sacrificed animals, grain, wine and under very unusual circumstances people in order to influence the gods to support them. Hints of human sacrifice appear in accounts at various, usually very stressful, times in Roman history. In fact, gladiatorial combat began as a kind of sacrifice that took place at the funerals of men who had great auctoritas.

A couple of other important religious acts included the votum and the lustration. A Votum was a vow or conditional sacrifice. The celebrant would promise some service if the gods would fulfill his request.  Lustration was practice borrowed from the Etruscans. One made a procession around something that one wanted the gods to bless. Lustration might be around pomerium (city limits). Basically the lustration involves the creation of a magic circle to provide divine protection for whatever is within the circle.

In the performance of the various Roman religious rituals there was one paramount requirement— the  ritual had to be performed perfectly. Any deviation from the traditional manner of the observance would violate the contract with the gods. If the rite departed in any way, no matter how trivial, then the whole thing would not work. If you started a ritual and made a mistake you would have to do it all over, sometimes with the addition of more rites to atone for the mistake. Failure in achieving the desired result could thus be blamed on the failure to perform the ritual perfectly.

The two most important things that Romans looked to the gods to insure were protection from their enemies and the fertility of their crops, herds and families.

The Romans didn’t really have a state religion per se. The most important aspect of Roman religion was the family cult, that is the worship of the gods and spirits associated with the family itself. In many ways, Roman national religion was simply the family cult written large enough to include the entire Roman community.

The Romans worshiped several deities within the family context.  Collectively the family gods and spirits were referred to as the numina of the familia. Some of these deities and spirits were attached to persons. The genius was the spirit that guarded Roman men and insured that they would have children to carry on the line. They also fulfilled a sort of “guardian angel” role, protecting the person from harm. In the familia, the genius of the pater familia received regular sacrifices in order to promote the fortune of the pater and his family and to insure that the family would be fruitful and multiply. Iuno  was a corresponding spirit for women. She did the same for women as genius for men—regular rites for the Iuno of mater familia.

The spirits of departed family members were called manes — always plural. Spirits of dead ancestors were always perceived of and worshipped collectively. Periodically Romans, particularly the pater familias, made sacrifices at the graves or shrines of ancestors to care for the manes and to encourage their support in this life. Sometimes if a family were about to undertake a particularly risky or dangerous venture, the pater familias might visit with the manes, make sacrifices, and seek some some omen that might be construed as advice on the subject.

A number of deities and protective spirits were attached to the family farm. Vesta was the spirit of the hearth. Most Indo-Europeans had a similar deity. It was important that the family hearth fire be kept going all the time to keep the vesta happy. It was the duty of mater familia to maintain that fire. On the first day of each new year, the fire would be put out, the hearth would be cleaned, and rekindled to indicate renewal of life. Vesta protected both the home and the fertility of fields.

Lares and penates were also very important protective spirits of the household and farm. Lares protected crops while they grew in the fields. Penates protected the store house. in addition to the lares and penates, a number of other deities protected various areas of the farmhouse. One is ianus the god of the doorway. Ianus had two faces. One angry face was turned outward to ward off dangers from outside of the home. The other, a kind face, looked inward, offered benevolent protection to all who lived within the confines of the home. The reason that a new bride is carried over threshold is to introduce this new member of family to ianus and in doing so, to include her within his protection.

In addition to the familial deities, a number of state deities were introduced. These might be called the greater gods who were associated with the interests of the Roman community as a whole. By the early Republic these had become specific cults devoted to distinct gods. At first, like the household gods, these state deities were seen as anima, protective spirits associated with the state. Later on, possibly as a result of Greek influences on Roman thought, they were seen as actual gods with specific forms and specific characteristics. Some of the gods of the state were family deities essentially writ large. Janus was the ianus of the state. Later most important state gods grew out of forces of nature. The principle god was Jupiter Optimus Maximus. He was originally a sky god, a typical Indo-European deity who brought rainfall. Etruscans gave Jupiter more importance as a fertility deity than the Romans did. Jupiter became sovereign god of the state — the equivalent of Zeus in the Roman pantheon.

Mars or versions of him, were worshipped all over Italy. In other Latin communities, Mars was the chief god. But at Rome, Mars had to share top position with Jupiter. Jupiter was the king of gods, but Mars was the patron of the Roman people. Because farmers were also soldiers, Mars was associated with both agriculture and war. Mars was most likely the Latinized form of the agricultural Etruscan god Maris. Initially the Roman god of fertility and vegetation and a protector of cattle, fields and boundaries, Mars later became associated with battle as Rome began to expand, and, under the influence of Greek thought, he was identified with the Greek god Ares. Unlike his Greek counterpart, Mars was generally well liked and rivaled Jupiter as the most honored god. He was regarded as the legendary father of Rome's founder, Romulus, and as such it was believed that all Romans were descendants of Mars.

In the Republic, the third deity, a god of the Sabines was  Quirinus. The Sabines had a settlement near the eventual site of Rome, and erected an altar to Quirinus on what became the Quirinal Hill, one of the Seven Hills of Rome. When the Romans absorbed the Sabine settlement they also absorbed the cult of Quirinus. Quirius was most likely a war god. He was replaced completely by Mars and no longer worshipped by the late Republic.

The chief female deity of Rome was Juno, which is most likely a variation of iuno, the genius of the mater familias. At first she was not very important, but she gradually acquired more importance in Roman worship. Greek influence equated her with Hera, so Juno became the wife of Jupitor Optimus Maximus. She is associated with fertility, childbirth other “women’s stuff.” Every year after around 300 B.C., women held a festival in honor of Juno called the Matronalia. Women would participate in rituals at the temple. On that day women wore their hair loose (when Roman decorum otherwise required them to wear it up), and were not allowed to wear belts or to knot their clothing in any place. At home, women received gifts from their husbands and daughters, and Roman husbands were expected to offer prayers for their wives.

The Romans had other gods as well. This lecture has by no means been exhaustive. But, I hope to have made a couple of important points. First, I have tried to stress the importance of the cults of family and farm, and secondly, I have tried to make the argument that, in many ways, the Roman state religion was, to a great extent, an attempt by Romans to create a national religion out that was, to all extents and purposes, the Roman family cult expanded to cover the entire community. The Romans were a “waste not, want not” culture. They already had a perfectly good set of religious values focused on the family, so why not simply expand the pre-existing cults to represent a national religion. They were also excellent borrowers, so they borrowed rites and deities from the Etruscans, and later made adjustments to their religion based on contact with the Greeks. In the end, they put together a serviceable system to maintain the peace between the Republic and the gods.