Steinbach belonged from the Early Middle Ages to the Glan-Münchweiler church, which was consecrated by Saint Pirmin and ministered to all churches in the Münchweiler valley. In the time of the Reformation, Steinbach, along with all the dwellers of the Münchweiler valley, had to adopt on the lord's orders Lutheran beliefs, leaning as the Leyens did mainly towards Palatinate-Zweibrücken's views when it came to religion, at least at first. In 1588, though, when Palatinate-Zweibrücken, then headed by Duke Johannes I, commanded all its subjects to convert to Calvinism, the Counts of Leyen resisted this order within their lordly domain. The valley's Christians kept their Lutheran faith, but were subject to an ecclesiastical administration that was directed from Zweibrücken. After the Thirty Years' War, the law conferred religious freedom, and indeed, among the newcomers to Steinbach, particularly at the time of King Louis XIV's War of the Reunions, were a great many Catholics. At the turn of the 19th century, one third of the Christian population was Catholic, a share that is still similar today. Today's Protestant villagers belong to the Quirnbach church within the Evangelical deaconry of Kusel, while the Catholics belong to the Glan-Münchweiler church within the Catholic deaconry of Kusel. The same is true for Frutzweiler.