We might be registered Republicans, or Democrats, or Independents. Or maybe we’re among those Christians like the Amish who don’t vote at all, and therefore don’t need voter registration cards. How we might participate in a national election, and in the politics of this world is not a given, one way or another. It’s not like one has to vote Democratic or Republican or some other party or candidate or even at all to be a true follower of Christ. The one necessity is that we follow the politics of Jesus in God’s kingdom come in him, which means for us the way of the cross in judgment against all the idolatrous pretensions of any nation state. See for a most helpful explanation of that, Politics of the Nations vs. the Politics of the Cross, by Allan R. Bevere.
The Christian answer for the Republican or Democratic or any other party is not the “opposite,” not libertarian, nor anything else at all except for the good news in Jesus which involves not only the cross of Jesus in his death and resurrection for salvation, but by that same cross walking in the footsteps of our Lord. Instead of finding our identity in any politic of this world, our identity already is in Jesus, which means in the most basic sense the Democratic, Republican, or any other party of this world is strictly speaking alien to us. We might tend to vote one way or another based on a number of factors, or again even not at all. What we must beware of and have no part of is to be subsumed into a politic of this world which at its heart cannot and actually is not identified with Jesus. That is in significant part because the way of the world always without exception is going to run against the way of Jesus, and God’s grace and kingdom come in him. The way of the cross in Jesus, as the above link clearly and from scripture points out is not the way of the world. The one is the way of death and resurrection not only in salvation, but in all of life in following Jesus, and brings life. The other is inevitably the way of death in that it is allied to a power that is of this world, and therefore inevitably allied or tied to what scripture calls the world, the flesh and the devil.
Our one answer to the world as Christians and professed followers of Christ is not an affiliation with one political party or another, never. Instead it should be our complete allegiance to God’s grace and kingdom come in Jesus. We are at home only there, finding our true identity in this world. Not as “Progressives,” “Conservatives,” “Libertarians,” or anything else. Because the gospel is not just about one’s personal salvation, but about all of life, and it is the one politic with the end of being for God’s kingdom present in and through the grace of God found in Jesus and lived out in and through the church in the world, and in a sense for the world, but never of this world.