This study investigates the phenomenon of violent preaching and its implications for peaceful coexistence between Christians and Muslims in contemporary Nigeria. The study is grounded in the theory of religious violence and social identity theory, the research examines the causes and consequences of inflammatory rhetoric in Nigerian society. Nigeria's history of ethno-religious conflicts, particularly in the northern and southern regions, has resulted in significant human and material losses.Employing a qualitative research approach, this study analyses existing literature and primary Islamic law sources to explore the factors contributing to violent preaching. The theory of religious violence suggests that religion can shape individual and group behaviour, sometimes leading to violent conflicts. Social identity theory further posits that individuals derive a sense of identity and belonging from their religious affiliations, fuelling ingroup-outgroup dynamics. Findings by the paper indicates that aggressive or militant preaching is a significant cause of religious violence in Nigeria. Other contributing factors include religious intolerance, fanaticism, poverty, and misguided religious orientation. The study highlights the devastating effects of violent preaching, including loss of life, property destruction, and psychological trauma.To mitigate the menaces of violent preaching, the research recommends promoting interfaith dialogue, regulating religious preaching, addressing poverty and inequality, and encouraging inclusive governance. By fostering a culture of peace, tolerance and understanding, Nigeria can work towards achieving peaceful coexistence between Christians and Muslims. This research concludes that violent preaching in Christianity and Islam poses a significant threat to peaceful coexistence in Nigeria, requiring a multifaceted approach that promotes interfaith dialogue, regulates religious preaching, and addresses underlying socio-economic issues.