How was religion dealt with in the Roman Republic and the Roman Empire?

In general, we see the religious atmosphere within the Republic and Empire being fairly tolerant, as is necessary, given the multicultural composition of the accumulated territories. There was much cultural assimilation of religion and fusion of some religions, such as the importation of Greek gods to Rome, with name changes. Romans also tended to maintain devotion to certain values, as evident by the worship of Lares, or household gods, and a cult of ancestors. Later, deification of the emperors expanded the pantheon of gods.