The first Christian churches we find in the archaeological record (Megiddo, Dura-Europos, Aqaba) are closely connected to the Roman military, beginning around the time of Philip the Arab. Paul’s “road to Damascus” in Acts and mentions of Damascus in Galatians (which also mentions Arabia) and 2 Corinthians
Three theses on Christianity
You should post a list of books you recommend on Christianity (other than the Bible of course).