Shortly after the death of Jesus ( Nisan 14 or 15 ) , the Jerusalem church was founded as the first Christian church with about 120 Jews and Jewish proselytes , followed by Pentecost ( Sivan 6 ) , the Ananias and Sapphira incident , Pharisee Gamaliel 's defense of the Apostles , the stoning of Saint Stephen ( see also Persecution of Christians ) and the subsequent dispersal of the church which led to the baptism of Simon Magus in Samaria , and also an Ethiopian eunuch . Shortly after the Death ( Nisan 14 or 15 ) and Resurrection and Great Commission and Ascension of Jesus , the Jerusalem church was founded as the first Christian church with about 120 Jews and Jewish Proselytes , followed by Pentecost ( Sivan 6 ) , the Ananias and Sapphira incident , Pharisee Gamaliel 's defense of the Apostles , the stoning of Saint Stephen ( see also Persecution of Christians ) and the subsequent dispersal of the church which led to the baptism of Simon Magus in Samaria , and also an Ethiopian eunuch .