Early Christianity originated in Samaria-Sebaste. That is where Jesus was crucified in 36 AD;
the protests that led to Pilate being recalled started there. Simon Magus was active there; he was the leader of the Gnostic Jesus movement, and in Christian tradition he became Simon Peter, the disciples’ and Apostles’ spokesman. The first baptismal community also emerged there, though it did not feature the Gnostic idea of receiving of the spirit at baptism; Acts 8:12; 16.
And the great speech of Stephen, the first Christian martyr, in Acts 7 expresses the spirit of James’ Samaritan Jesus movement: Stephen refers to the Samaritan Messiah, the Taeb: Acts 7:37 = Deut. 18:15.
Philip’s mission in Acts 8 starts there and Luke continues the Acts of the Apostles there too, only interrupted by Paul’s conversion, and Peter’s missionary activities in Lydda, Joppa and Caesarea Maritima.