Research on public speaking has recently made fair progress within the CSCW scholarship that mostly focuses on training speakers to gain popularity. Core to this research is the idea of a universal set of skills that makes a public speech successful in terms of popularity. However, a strand of research has also shown skepticism to this simplistic conceptualization of the speaking context. We join this discussion by presenting a mix of qualitative and quantitative analyses of Islamic preaching videos on YouTube. These videos are created from Islamic sermons -- a form of Islamic religious public speaking in Bangladesh. By exploring the topics of discussion by the preachers and by analyzing the performances of the preachers during the sermons, we demonstrate how those are situated in their social, political, and religious context. Based on our findings, we discuss how the public speaking scholarship of CSCW and related fields could benefit from studying such public speeches in non-secular contexts of the Global South. Further, we discuss how the role of such religious sermons could contribute to the development discourse within CSCW.