Obviously, this would be a lot easier to address if you had a specific passage. I’m pretty sure that Paul advises his followers to live peacfully and to obey the magistrates or governmental leaders. I don’t remember a specific passage where he addresses their relationship with non-believers, but it would seem that at the time of Pauls ministry they would have been pretty much surrounded by non-believers. As I understand the Church history (and I’m no expert), the Church was comprised of small enclaves or even smnaller groups of converts often trying to live under the radar as it were. The full-on persecution of Christianity had not quite gotten going but it was certainly frowned upon. Remember, it was in Antioch, a church founded by Paul or one of his missionaries where the word Christianity was first used. I’m not sure, but I think at this time it still wasn’t clear that this new way of believing was seperate from Judaism or a form of Judaism. So, these early Christians were caught between a clearly unfriendly Jewish crowd and a probably more unfriendly Roman authority. So, I guess you could infer that Paul was expecting the members or believers to live in peace with their neighbors as much as a Christian ideal as for survival. Remember, Paul was a Jew and their laws and rules were rooted in practical concerns as much as spiritual matters. I doubt Paul could have completely gotten rid of that tendency to balance the spiritual with the practical. Just my opinion. I’ll watch from the shadows so I might learn somethinga bout this as well.
