As long as the human society exists, social vices will remain inevitable. These social vices include cultism, thuggery, kidnapping, sexual abuse, fraudulent behaviours among many other vices. Given that the church has done her part in helping the society as a social change agent, there is scarcity of research on how effective the work of the church has been in developing nations especially in Nigeria. It is on this premise that the objective of this study is set to determine the role of church promotional activities in influencing a new convert's intention to change his/ her behaviour. The population of study was One hundred and twenty five newly converted Christians. This is a complete enumeration method (Census method) of three provinces that were involved in the believer's foundation classes as at the time the research was conducted. It was discovered that, the church's promotional activities play a significant role in influencing new believers' intention to change behaviour. In order to successfully change the behaviour of people, churches must ensure that the social environments of these new converts are engaged in the process to ensure a long lasting change in behaviour of the newly converted Christians.