Then as now, the church was the center of the village. The lower part of the mighty church tower dates back to 1302. Up to the present day, the church has undergone several renovations in the years 1483, 1567, 1742 - 1748 and 1936 - 1937. The patron saint of the church is St. Sebastian, whose feast day is celebrated on January 20. His image is in the middle of the high altar. Originally, the church seems to have had two patrons. One was St. Stephen and the other St. Sebastian. In 1742, parish priest Michael Hepp wrote in the church register: “According to ancient letters, the old parish church in Rosbach was called St. Stephen's. Both holy martyrs Stephen and Sebastian were its patrons and presumably St. Stephen was the first or principal patron. St. Stephen is commemorated on December 26.
However, after the great pestilential plague (1666) in the last century caused devotion to St. Sebastian to increase greatly in this mountain (Haardtrand), the local community began to have a special devotion (veneration) to St. Sebastian as the 2nd patron saint of the church. A plenary indulgence is sought on the feast of St. Sebastian (January 20). This means that St. Sebastian is consistently and definitely regarded as the first principal patron saint of the local parish church, not only by the community, but this has even been incorporated into the Directoria (official instructions). Even in the Middle Ages, the parish church had two side altars, as it still does today - four patron saints, namely the Virgin Mary, John the Baptist, Bishop Nicholas and the martyr Catherine. The other was dedicated to St. Abbot Wendelin, typical of a farming village. Also worth seeing is the medieval sacrament niche in the basement of the tower, where the main altar once stood. The organ was built in 1913 and the bells were consecrated in 1950. The present parish church in Roschbach is one of the most beautiful baroque churches in the diocese of Speyer. The architecture of the church was designed by Albert Boßlet in 1936 - 1937.