There has always been an escapist segment in the church, sometimes heretical (Gnostics, Cathari). The monasteries were a mixed phenomenon, combining escape from the “world” with affirming and promoting education, music, hospitals, and works of mercy. After the Reformation, the church’s relationship to the world became more varied in practice. Anabaptists rejected the legitimacy of the civil government. The Reformed, Lutheran, and Anglican traditions developed somewhat different postures but affirmed the Christian’s role in the world. Liberalism converted Christianity into the social gospel. Postmillennialism optimistically hoped for the Christianization of the nations. Dispensationalism warned of the impending rapture and the uselessness of any church activity beyond evangelism. In Reformed circles, marked differences are present in the different theological approaches to engagement with the world. Things have indeed become more complex.
Gerard Van Groningen has a wonderful series of Bible commentaries, From Creation to Consummation, in which he traces what he calls the “golden cord” throughout the Scriptures. He might not be the first to use this imagery, but he does a wonderful job of biblical exposition from the Hebrew text. The three strands that bind biblical revelation of God’s work in history are kingdom, covenant, and mediator. God is King, and His covenant relationship with a redeemed people is the most wonderful and visible evidence of His lordship. And at the center of both God’s kingdom and God’s covenant is Jesus Christ the Mediator.
When the church sees itself as not only a group of saved individuals but also the visible evidence of God’s kingly-covenantal activity on earth, the metaphors of “salt” and “light on a hill” become natural modes of existence (Matt. 5:13–16). The church doesn’t simply “do” salt and light things once in a while; the church is the salt and light of the King. As John Calvin commented on Psalm 2, Christ’s universal kingship knows no limits, no boundaries. God’s covenant in Christ creates a new humanity. And this explains why even under persecution, Christians saved discarded infants, cured the sick, buried bodies left to rot, and blessed rather than cursed their accusers. They were a new humanity infused with the hope and the power of the age to come.
If God is re-creating a new humanity whose purpose is not only to be salt and light but also that men might “praise our Father in heaven” because of us, we are left with no alternative than to consider the world’s non-salty darkness as antithetical to the Christian’s entire worldview. Christians are called to be a kingdom-honoring covenant community seeking Christ’s glory—in everything we do.