You might interested in some previous threads on Roman interaction with foreign, non-Abrahamic religions some of which are from the FAQ section on "Religion in Ancient Greece and Ancient Rome":

• Did the Romans think of their gods as Roman gods, or as gods period? (In other words: when the Romans imposed their gods on conquered peoples, was this part of how they imposed Roman supremacy? Or could one worship the Roman gods without reference to Rome -- a universal religion, like Christianity?) - 88 comments, over 12 months old.
• This thread attracts several flaired users who also talk about how the Romans equated their gods and foreign gods to each other.
• Did the Romans prosecute people of different religions? Ostracize them? - 11 comments, over 1 year old.
• This thread discusses the criteria that generally determined which religions were persecuted and which weren't.
• Why were the Romans so fervent on exterminating Christians, yet they were tolerant towards other religions in the empire? - 27 comments, over 2 years old.
• The commenters in this thread explore what religion and religious practices meant for the Romans and thus relate it back to how the Romans thus interpreted foreign religious practices.
• When Romans conquered land, did they interfere with the religion of the natives? - 12 comments, over 1 year old.
• This thread brings up a large number of linked references which you may want to read to get a better picture of Roman views on various religions.
• How did the Greeks/Romans treat gods of other pantheons? - 5 comments, over 1 year old.
• A commenter pulls a quote from a Roman historian to show how the Romans saw foreign gods.