I've heard conflicting information on this. What I was taught was that the Romans followed the Greek Pantheon with latin names (Jupiter, Neptune, that sort of stuff). However I've also read that many a emperor made worship of them mandatory, or, at least highly recommendated.
When I still had Sunday School (and I do not know how accurate this information is) I was told that the Romans had some sort of "freedom of religion" in their outskirts, which was why Israel still had the ability to have temples.
Being confronted with such a vast array of information, I would like to know which one is the correct one. Was there one single, Senate endorsed religion? I know that the Roman Empire lasted a good couple of centuries (millenia even if you count the holy roman one), does that mean that there were changes in religion for brief periods only?
Thank you
The Romans had an official state religion based on the worship of Jupiter, Juno, etc - basically the same pantheon as the Greeks (and probably imported from much earlier times) with a few exceptions. Following the fall of the Republic, the emperor was also considered divine, and sacrifices to his person were mandatory on most citizens through much of the Imperial period.
The Romans had a very tolerant policy regarding religious beliefs of subjugated peoples. They had no problem allowing others to keep their native beliefs, provided they also acknowledged the divinity of the emperor.
There was a more curious relationship with he Jews, the sole monotheistic people of the Empire, and one that refused to accept any god but their own. The Romans took a pragmatic approach. Since the Jews had such a long tradition to follow, the Romans let them continue to do so as long as they paid their taxes and didn't cause any other trouble. (This "not causing trouble" ended abruptly with the First Jewish Revolt in AD 70 when the Second Temple was destroyed and many Jews expelled from Judaea, and more or less completed with the end of the Second revolt about 50 years later)
Later in the Imperial period, the cult of Mithras was imported from the east, and especially made a lot of inroads with the army, but was never adopted as an official religion.
The Empire had a very different relationship with Christianity. There were features of it that made it less acceptable than Judaism had always been. Like the Jews, the Christians refused to accept the divinity of the emperor. But Christianity was not an ancient religion that predated Rome itself. They held that a man who had once walked the Earth was in fact God. And unlike the Jews, who were as much a culture as a religion and were content to stay put in their homeland far on the frontier, Christianity was a proselytizing religion and was spreading through Anatolia and Greece, part of the heartland of the Empire. Official persecutions occurred as late as the reign of Diocletian in AD 303.
All that changed with Constantine I. Constantine first legalized it in stages between 306-313, then made it an official religion of the Empire in 324, and finally converted to it himself (possibly on his deathbed).
See Robert Turcan, "The Gods of Ancient Rome: Religion in Everyday Life from Archaic to Imperial Times"