Matt. 5:13-16 is significant in the understanding of the Sermon on the Mount. It forms a transition from identifying those who are to live according to the demands of the Sermon on the Mount in the present (5:17-7:27) and those who will live the life of blessedness in the future (5:3-12). In this transitional passage, the audience is metaphorically identified as “The salt of the earth” and “the light of the world.” Using these metaphors to describe the audience draws attention to their usage in normal life situations. Equally, the metaphorical understanding of these elements both in biblical and social parlance is instructive. For instance, salt is a sign of covenant while light is a sign of orderliness and progress. Salt must lose its physical qualities before its preservative and flavouring effects could be noticed. In the same way, candle as source of light degenerates gradually as it gives its light till it burns itself out for the good of others. So when Jesus uses “salt” and “light” to refer to his disciples he means that they are to be to humanity what salt and light are. He urged his followers to become the salt and the light in the world that is hostile to God, lost in sin, ruined, and even depraved. This text was studied within the Nigerian Christian context. Within this context, there are so many Christians, and at the same time there are so many elements that tend to hinder the full realization of their Christian vocation of being salt and light, though not insurmountable. These elements are structurally imbedded in the socio-political, economic, and religious organization of Nigeria. These elements include double allegiance, bribery and corruption, etc. This book studied Matt 5: 13-16 in the context of Christians in Nigeria. It discusses the theological implications of being salt and light in the context of Nigeria. It established that Christians in Nigeria understand their worth as “salt” and “light” to the Nigerian nation, but the only problem is the will-power to fulfil it despite the socio-cultural and political context of the nation, Nigeria. Hence, it affirms that there are societal and existential challenges to being salt and light, and that it is only by overcoming these challenges that Christians can truly be salt and light. That is, how they understand, relate, and respond to the challenges of this text in their day-to-day life within the prevalent context that determines their Christianity. The book discusses the theological implications of being salt and light in the context of Nigeria. The metaphor of salt and light, therefore, as applied to Christians from the metaphorical and theological perspectives signify that they must preserve the Nigerian nation and its people from the putrefying effects of hatred, violence, injustice and ethnocentrism. As salt and light, Christians must purify and heal minds and hearts of corrupt and evil ways, and administer the life-giving Gospel message implied by the Sermon on the Mount to keep Nigeria and its people alive. Some of the recommendations we arrived at in this book among others include: Christians should rise to the challenge of Matt 5:13-16 in their environment no matter what; Salt and Light are encouraged to be used as Sacramental more than ever. Significantly, this work will be of immense assistance to Christians in Nigeria as well as Christians all over the world.