Jesus came from God the Father with the message of salvation. In order to make this massage reach to the ends of the earth for the evangelization of all, both the Jews and Gentiles, he selected twelve apostles out of the disciples that followed him. These twelve he molded and made the “light” of the world and “salt” of the earth and urged them to let their light shine so that people will see their light and glorify their father who is in heaven (Matt. 5:13-16). It is this twelve that followed him from the inception of his ministry to the end of his ministry. The implication is that they were with him from his baptism to his ascension. Having formed the Twelve, he sent them on a mission to evangelize the whole world. The aim of this article is to restate anew the inseparability of formation and mission in the work of evangelization and their indispensability in the work of evangelization. This paper argues that if the mandate of Jesus in Matt. 28:16-20 is duly understood and imbibed then formation, and re-formation of evangelizers cannot be over emphasized. Significantly, the outcome of this research will be of immense benefit to all evangelizers and missionaries all over the world.