The state is not free to run its affairs pragmatically; moral demands are laid upon it by God, and judgment awaits those officials who turn aside from ruling according to the just standards established by the Lord. For this reason the New Testament and its preaching is not apolitical.
My two cents
Most people recognise the political (i.e. theocratic) nature of the Old Testament, but I’ve heard some people say that since believers in the New Testament were under the political rule of the Roman Empire, Christians ought to remain apolitical or under the rule of someone else. I don’t really agree with that line of reasoning—I’ll go with Bahnsen’s line of reasoning instead. I don’t imagine that politicians will be exempted by God’s judgement on the basis of (humanistic) diplomatic immunity or Parliamentary privilege.
Bahnsen, G.L. (1979). Theonomy in Christian Ethics. 1st. ed. Nutley: Craig Press, p. 391