Christianity had elements from Egyptian religion--Osiris rose from the dead and judged the dead. In Greek Dionysian religion there was a ritual consumption of the flesh and blood of the god. Christianity can be thought of as a branch of Judaism.
Everett Ferguson (Backgrounds of Early Christianity) says, "That which is truly unique to Christianity is Jesus Christ." He says that what would make Christianity unique in an absolute sense, with no possible historical rival, would be for Jesus to be what is claimed for him - that he is the Son of God. "There we pass from history to faith."
The Romans made Christianity a legal religion in 313 AD. After this date, Christianity along with all other religions was legal and allowed.
The Romans respected other religions.
The Romans tolerated other religions as long as they were not what the Romans considered decadent or treasonous.
King Louis was from Rome and all the Romans were tolerant of other religions as long as their followers were respectful of the Roman religion.
Joseph Shulam has written: 'A Commentary on the Jewish Roots of Romans' -- subject(s): Bible, Christianity, Christianity and other religions, Commentaries, Judaism, Relations, Theology
The Romans never banned the religions of the other peoples of the empire. They tolerated and respected the religions of the conquered peoples. When Christianity spread around the empire, there was a number of persecutions. However, Christianity was never banned. The only instance of banning religions was when mainstream Christianity (the Catholic Church and the Orthodox Church) was made the sole legitimate religion of the empire (and therefore the state religion) in the Edict of Thessalonica of 380.The purpose of the edict was to ban dissident Christian doctrines, which were branded as heretic. The dissident sects, particularly Arian Christianity which was popular around the empire, were then persecuted.
The Romans were tolerant of others' religions as long as those religions or beliefs did not provoke dissent or preach treason. This became a problem during the rise of Christianity, as any religion other than the religion of the Roman state was deemed treasonous to Caesar.
Hinduism and Islam are two other religions in India.
Christianity.
The Romans were generally tolerant of other religions as long as the participants also honored the Roman gods.
Ancient Romans let people to keep their own religions when they conquered new lands. That made the conquered people easier to adapt to the Roman culture. Romans built temples for their own gods in the provinces, but they let people to worship their original gods as well. Only after Christianity became the state religion, they started to keep other religions pagan and finally forbid them. Christianity was more intolerant than other religions before it.
Islam and Christianity