When it comes to politics we can get really confused if we mix up our national sympathies with our Faith. Much damage has been, and continues, to be done when faith is used by demagogues to further their own ambitions. Hitler himself leveraged faith in his rise to power in Germany
Hence today I believe that I am acting in accordance with the will of the Almighty Creator: by defending myself against the Jew, I am fighting for the work of the Lord. - (Mein Kampf)
An even more recent example might be the current political campaign of Donald Trump (2016). Trump used rhetoric designed to pull in people who view America as "God's Country".
It's important when considering what your faith requires of you in politics, that you make a distinction between human philosophies and scriptural wisdom. You don't want to fall into the trap of worshipping a philosophy or person at the expense of the Author and Source of your Faith. No form of government currently in use has been mandated by God anywhere in Scripture.
As an American Christian, I'm surrounded by Christians who act as if America was a nation founded as a sort of de facto theocracy by God himself. If you are an American Christian maybe you are in that camp. I would like to convince you otherwise though. The reality is that we are not in fact a Theocracy but are instead , at least on paper, a Representative Democracy with an economic policy that is largely capitalist in nature. Both of which are human created philosophies and, as such, are flawed and incomplete by nature.
If you are a Christian one fact should be indisputable for you. The ideal form of Government is a Theocracy. When I say Theocracy, I mean a specific form of Theocracy. Government directly by God himself. I'm not talking about government based on scriptural principles. This is a subtle but important distinction. The only Theocracy fitting this definition in Scripture, and I think in all of history, was the government of early Israel. It's uniqueness and singularity are worth thinking about.
Some of what makes Israel's Theocracy unique and noteworthy is how it came to be. In Exodus 20-24 we read about the formalizing of Israel's theocratic government. Note in these passages that God is the initiator. It is God who writes the laws of Israel. He writes the moral laws. He writes the economic laws. He writes the laws concerning social responsibility. He tailors them to the nation of Israel. Then He calls the people to accept them1. For as long as they lived under this Theocracy, God was active and present as their King in a way we have not seen since. This is why it's such a tragedy when the people of Israel called for a King2.
The response from God here is telling. (And the Lord told him: “Listen to all that the people are saying to you; it is not you they have rejected,but they have rejected me as their King")3 This is the point in their history that Israel rejects their theocratic government out of fear and a lack of faith. Because of this rejection, the kind of theocracy that Israel enjoyed for a brief period of time has been unavailable ever since. It was unique and God has not called any other nation in that way.
So what then should a Christian look for in Government if Israel's Theocracy is unavailable to us?
Since we don't have the Theocracy option available to us yet (see Revelation 21), but still have to participate in Government, what should our approach be? Scripture still has plenty to offer even if it doesn't outline a detailed plan of government for us. Specifically it addresses a couple categories around government.
Humans, biblically speaking, are a fallen4 and corrupted people5 . Even Paul, as strong of a Christian as he was, struggled with his Human Nature6. This principle of Scripture should indicate that none of us can be fully trusted to govern. Anyone who governs needs accountability and transparency to avoid going down the path that our human nature will naturally follow.
We also see in scripture that we are fundamentally limited. We do not have God's omniscience or power. We make mistakes as a result of incomplete information or just lack of ability. We won't get it right on the first try, or the second, or even the third. This principle of Scripture should indicate that no human formed law or statute is sacred. We need, and indeed should, constantly look at our our governmental systems with a critical eye. We should be willing to modify them as new information becomes available. We should expect that they will need modification.
In the Gospels the disciples ask Jesus about taxes. He holds up a coin and asks whose image they see on it. They answer "Caesar". His response is interesting. "Render unto Caesar what is Caesar's and unto God what is God's"7. Jesus was pointing out that there were real benefits to Roman rule. Trade, Infrastructure, Protection were all provided by Rome. The Jews benefited from all of these. There was no scriptural support for partaking of that benefit without respecting the authority that provides it. In fact if you read that passage you will see that Jesus calls such an attitude hypocritical.
Paul, in Romans 13, makes the point that all authority comes from God8. If you find yourself under a form of Government then you are commanded to respect the leadership. Insofar as that Government's edicts do not cause you to sin, you are under a Christian obligation to obey them.
Finally we as Christians have some additional responsibilities. We are to care for the poor, the widowed, and the orphaned. We are to prize justice and also mercy. We recognize that God grants everyone the right to reject Him. We recognize that people must be able to freely choose Christ which means they must have religious freedom.
If you understand the above then some practical applications become evident. We must approach any law or statute with the understanding that they are by default suspect. They can and in fact are likely to be incorrect. They will at some point in time be in need of revision. They will at some point in time be incorrectly applied. Whatever your favorite or most fiercely defended law or statute may be, never forget that it was formed by flawed human beings as part of a flawed political system for flawed reasons. As a christian, if you put a political system, or a law or statute on too high a pedestal, you may be guilty of a form of idolatry. Your attitude indicates that you prize that system more highly than you do the principles of Scripture. You don't live in a Theocracy because God has not set one up for us. You do live in a political system created by people. Don't treat those people or that system as flawless. Only God can claim to be flawless and He tends to be jealous of anything that takes that label instead of Him.
It's also important to evaluate any proposed system, statute, or law on its merits scripturally and not with knee jerk reactions to the philosophy it's authors come from. Socialism has many distinctly Christian motivations. Democracy does as well. Even Communism has a few things to recommend it Scripturally speaking.
Let's take a look at a practical example. Somewhat recently healthcare was a topic of quite a lot of debate here in America. There was talk about moral hazards, laziness, personal freedom, budget constraints, and compassion. So if we approach Healthcare reform from a Biblical perspective what should be the criteria whereby we measure any proposal?
Healthcare is a particularly interesting example. When it comes to life-threatening emergencies almost no one turns down lifesaving treatment. The value to an individual is effectively infinite. But supply is of course limited. It is arguably cruel and immoral to deny someone life-saving treatment and of course in America it has long been the case that you were guaranteed stabilizing treatment if you went to an emergency room.
However just as we will rarely if ever turn down lifesaving treatment in an emergency we will frequently engage in long term hazardous behavior. This is due to laziness, selfishness, or simple ignorance. The value of habits and behaviors that will benefit our health are frequently of much lower value to us.
Knowing what we know about human nature we need a system that balances these two economic facts concerning healthcare. Ideally we want to account for the reality that, for many people, healthcare costs will be put off till they are at their most expensive and of the highest value.
Biblically we are commanded to care for the sick, and the poor. God holds us responsible for their healthcare and well being9. It's not enough to say "not my taxes" if we also say "not my tithe". We don't get to say "it's not my problem" because Jesus made it our problem. If we can't get our Church and other nonprofit organizations to make a dent then it's on us to find another way.
Despite the above you can't just throw money at the problem either. Knowing what we know about human nature and how money corrupts us, we need to ensure there is enough transparency and accountability in whatever proposal we support to counteract it. There need to be clear expectations and clear consequences for not meeting them.
We also can't support a program that spends more money than is being brought in. If our preferred proposal requires raising taxes then we need to admit that and accept it. If it requires cutting funding for something else then we we need to do so. What we shouldn't do is expect a future generation to pay for it.
We are flawed human beings. We won't get it right on the first try. We'll need to adapt whatever may get implemented. Cultural changes may require new approaches. Unintended consequences may require us to tweak or outright change things. We may even need to scrap it and start all over. It's not a failure it's just the reality of being human.
1: Ex 24:3 - https://www.bible.com/bible/59/Ex.24.3.esv And all the people answered with one voice. "All the words that the Lord has spoken we will do."
2: 1 Samuel 8 - https://www.bible.com/bible/59/1.Samuel.8
3: 1 Samuel 8:7 - https://www.bible.com/bible/59/1.Samuel.8.7.esv And the Lord told him: “Listen to all that the people are saying to you; it is not you they have rejected,but they have rejected me as their King"
4: Genesis 3 - https://www.bible.com/bible/59/Gen.3.esv
5: Romans 3:23 - https://www.bible.com/bible/59/Rom.3.23.esv For all have sinned and come short of the Glory of God.
6: Romans 7 - https://www.bible.com/bible/59/Rom.7.esv
7: Mark 12:17ff - https://www.bible.com/bible/59/Mark.12.17.esv
8: Romans 13 - https://www.bible.com/bible/59/Rom.13.esv
9 Matt 25:31-46 - https://www.bible.com/bible/59/Matt.25.31-46.esv