The thrust of this paper is a theological understanding of conversion which comes from text-driven biblical preaching and its missiological imperative for Christian missions in Africa. The study adopted a descriptive approach to discuss conversion as it relates to missions from Lukan perspective in two passages; Luke 13:7-14 and Acts 2:14-38 noting that conversion and fulfillment of the Great Commission is central and critical to these texts. Inferences drawn from brief expositions of the two texts revealed that conversion is the need of everyone and authentic proclamation of the Gospel is important for true conversion to take place. It is also inferred that true conversion coming from repentance and having faith in Jesus Christ as Lord and Saviour should reflect in a new way of life or transformation evident in simplicity and care for others. The study submitted that it is imperative for contemporary church in Africa to understand conversion as necessary to rid the nations of different menace including corruption, ungodly leadership and poverty. It is also imperative for the church in Africa to proclaim the gospel capable of resulting into conversion and transformation by engaging in expository text-driven biblical preaching, lifestyle evangelism, and demonstrating the power of God through signs and wonders. The delivery of the word of God must be accompanied with effective exposition of the biblical text through preaching to stir the heart of the hearer to true conversion.