I am affraid you got something wrong in your paradigm of history.
Romans were pagans. And they were persecuting Christians.
What they did? I am really puzzled. At best you could conclude, part of our ancestors accpted Christianity, other part was not happy with choice of former, so they offten clashed.

That is false, the rulers were the ones that accepted Christianity, blinded with the wealth they were offered, or they simply wanted to get married to a Christian princess, but the princess naturally wouldn't want to convert to Paganism. The rulers and their heirs persecuted those who followed the national religion, but found it difficult. In Serbia, the last Pagan temple was demolished during the reign of Tsar Dushan, in the 14th century! Fortunately enough, our faith is recovering, although quite damaged.