Jesus calls his followers the salt of the earth. And the light of the world, and compares them to a city built on a hill for all to see. Just how are we as Jesus’ followers, his church, to impact the world? I say now his church because since Pentecost the Spirit has been poured out on us in Jesus so that we are witnesses in word and life individually and as church.
This is not at all an easy question, evident from Christians being all over the place on it. But by and large the mainstream of Christianity since the Constantinian shift has advocated a very hands on, participative approach. So that in their view, God’s grace and kingdom come in Jesus is for the transformation of all of culture (what can be redeemed) here and now, as well as for the conversion of individuals. Or instead of the transformation of culture, a needed participation in a kingdom which is provisional for this time and accountable to God.
And actually the present day answers or positions from Christians on this question are nearly maddening in their variety. Anabaptist nowadays might want to be different as in standing apart, but with the desire to see that difference play out in the state. Whereas Anabaptists of old, or the more traditional would generally say something like, “Let the state be the state. That’s all it can be. We are called to be different.” The answer may well be somewhere more in between those two extremes. We can’t expect the kingdom of this world to become allied to the kingdom of our God and of his Christ/Messiah. At least most of us would insist that the “not yet” includes the difference between the two kingdoms until God’s final judgment when justice comes in the person and reign of King Jesus.
I am not settled on an easy answer, myself. I know there are strong followers of Jesus, I take them to be such, who think participation in the state and in the military can be better than a necessary evil, though they certainly would consider the need to kill an evil in and of itself, even if it is sanctioned by God and included in the good in Romans 13. The biggest danger seems to me to be that the church can be swallowed up into the state, so that the state’s purposes are served by the church, the state using the church for its own ends (see Allan R. Bevere’s important contribution on this: The Politics of Witness: The Character of the Church in the World). And the danger that the church might both participate in and bless that.
A better view would be to accept the differences and see Christian participation in hopefully wise ways, as we see in the Daniel of old. And Erastus of Corinth who seems prominent in the early church was involved in civil government.
Wherever one lands surely the church must show something better, something not of this world as in source and manner, but certainly for this world. Key for me in the end is the call to take up the cross. Something the state seemingly can’t ever do, something it isn’t called to do. Only followers of Christ as his church are called to do that. And in doing so to point to something beyond, which hopefully has impact for good even now.
Easy cut and dried answers really are not in keeping with either life as it is, or scripture as given. Even as we always and forever now seek to follow Jesus in the way of the cross.