Throughout various phases and epochs of Islamic history, the mosque’s functions have fluctuated and adapted to the political, economic and social realities of the time. To understand the diverse roles of the mosque today in traditionally Islamic and non-Islamic societies, it is necessary to understand how mosque functions evolved, changed and were sometimes reincorporated after long periods of dormancy. This study examines the increasingly significant role of the mosque, especially through their influential Friday prayer sermons (khutba), for empowering socio-economic dimensions in the moderate Indonesian Muslim society. Friday sermons which had been commonly dominated by religious themes have been progressively reformed by inserting more relevant and essential messages for socio-economic empowerment. A very historic Kauman mosque in Semarang, Central Java, has been demonstrating as a dynamic institution capable of responding to contemporary social needs. Islamic scholars and practitioners from different fields have been encouraged to deliver Friday sermons to enlighten the Friday congregation on how to deal with contemporary circumstances. Apparently, the Kauman mosque’s strategy is to try to bridge the gap between religiously oriented and contextualized approaches in propagating Islam. However, the dynamic social environment surrounding the mosque will determine if mosques will be properly operated for religious, political, or socio-economic functions. This study suggests to maintain both social and cultural bases surrounding the mosque for a sustainable reform effort.