For Platt, the Christian faith is a global one, not only in terms of the current demographic makeup of its religious community, but also in its mandate, which touches Christian practice at the individual and communal levels. That is to say, Platt views Christianity as a faith in which believers must be engaged in the plan of God to spread his gospel and make his glory known to the ends of the earth. He traces this plan to the original commission which God gave humanity upon its creation, as recounted in the book of Genesis: to multiply and fill the earth (which Platt extends further than its simple biological sense, and includes the Christian mandate to multiply by making disciples). Platt roots this sensibility not only in the Old Testament, but in the New Testament as well, noting that Jesus’s final commission to his disciples is a command to go out and make disciples of all nations. Since this idea appears in the foundational divine commissions to both the original Christian community and to all of humanity, Platt sees it as a core expression of what it means to be Christian: “[This] is the great why of God. God blesses his people with extravagant grace so they might extend his extravagant glory to all peoples on the earth” (69).

Platt sees this global and missional context as affecting both the individual and communal levels of Christian practice. On the individual level (as the primary audience of Radical is individual Christians), Platt advises his readers to get engaged in the life of global Christianity. “The message of biblical Christianity is ‘God loves me so that I might make him […] known among all nations’” (70-71). He suggests several ways in which missional engagement can be done, and some of the steps of his “Radical Experiment” at the end of the book are focused on this theme. He advises Christians to pray for every country of the world, to give generously to alleviate the sufferings of impoverished people around the world, and to spend time in another context rather than just staying in their comfort zones.

On the communal level, Platt sees global and missional engagement as one of the core elements of a healthy church. He regards this communal element as crucial: “The goal is not just for us as individuals to follow after Christ but to join together in communities of faith, denying ourselves, taking up our crosses, and following after him” (205). He goes so far as to redefine church as a “multiplying community” in Chapter 9. A church should be missional—that is, engaged in God’s mission to see the message of the gospel spread to the furthest reaches of the earth—and, as a result, it should be global in its perspective. Churches cannot limit themselves to attending only to the needs close at hand, but must take up the mantle of serving both local and global needs, in obedience to the commands of Scripture. To do less would be to resign to sharing only part of God’s heart, rather than embracing the whole.