From the beginning, Rome was a land of many gods, and as it grew, its inhabitants followed more and more doctrines and worshiped more deities. When the Empire conquered Greece and the Orient, it was, in turn, conquered by the religion of these peoples. By the end of the imperial period, dozens of cults dominated different parts of the city. Mithraism was popular among soldiers, while the Isis cult had a large number of female supporters. Many Romans preferred not to take risks and worshiped several gods at the same time. It was not uncommon to find images of Mithras, Jupiter and Jesus in the same house, as well as a small altar to satisfy the old homes or spirits of the house.
One of the reasons for this religious diversity was that Rome's original religion was not emotionally satisfying. Procedures before the gods were observed with the same attention with which the Romans viewed their contractual obligations. There was little promise of an afterlife or greater reward. It didn't make much difference while the Republic and Empire were prosperous, but the people began to look for a religious "salvation" when times of crisis arrived. The old gods were unable to provide this salvation, and the Romans eventually turned to beliefs elsewhere. In the fourth century, Mithraism and Christianity were the most popular among the new religions. Both provided a reason for existence, promised a better life after death, and had much more emotional appeal. At the same time, Eastern beliefs invaded the Empire, Rome's new leaders were creating new gods, deifying themselves. Several emperors became gods after death, and some tried to do so while they were still alive. The imperial cult was as empty of emotion as the cult of the old gods. That religion was a social convention. When the Roman citizen made a sacrifice in honor of the old gods of the Empire, he was reaffirming his loyalty to the Empire rather than expressing his religious belief.