This article has assessed Interreligious Hate Speech as a Source of Insecurity in Nigeria. It concentrates mainly on Christianity and Islamic religions’ hate speeches against themselves using the Speech Act Theory. The speech act theory according to Austin (1978) has three assumptions; locutionary, illocutionary and perlocutionary acts which explain that a speech made is referential, performative and result effective respectively. The research uses the theory with the intention that it covers what the hateful speech (referential) is, the reaction of the person to whom the hate speech is referred to (performative) and the consequences of the reaction of the victim (result) which in most cases are attacks. The work uses descriptive research design and its data is achieved through an observational method which sourced data from both primary and secondary sources (documented materials) and the data is analysed using a qualitative technique. In relation to the related existing literature, the work has achieved the reality of the struggle between Christians and Muslims in their battles through offensive words (hate speeches) which culminate to crisis in Nigeria. This study points out the linguistic implication of crisis/insecurity in Nigeria through religious people and suggests that government should put in place control mechanisms that can regulate the use of language to curtail hate speech that degenerate into insecurity in Nigeria.