Although it may seem to be, Moral Relativism is nothing new. When God is away, the sinners will play, and in Judges 21, we see such a scenario play out before our very eyes, as Israel had no visible ruler. The result: Complete anarchy. Every man did what was right in his own eyes. But as Thomas Hobbes once quipped, life in such a society would be "...nasty, brutish and short."
And so we have governments. These are organisations whose existence is primarily designed to maintain peace and freedom. This is why Christians are commanded to submit to authorities, pay taxes to authorities, and pray for authorities.
Unfortunately, in our modern world, Moral Relativism does not necessarily require the absence of the government, because Moral Relativists have actually infiltrated it. And so, rather than being a force for peace and freedom to worship, the freedoms the government defends most often now is the freedom to do what is right in your own eyes as opposed to what is right in the eyes of the Lord.
But as I once pointed out to an abortionist, "you are not the only murderers out there". Indeed, even Richard Dawkins confesses that he has mixed feelings about the decline of Christianity, because he acknowledges that it is a Bulwark against something worse.
As a general rule, whatever you give the government the power to do to others, you give them the power to do to you. Even a law left behind by a good government may be exploited by future tyrants. I was especially amused when, after the 2016 presidential election, the same anti-gunners who claimed a Nazi system would be impossible in America began squawking about how Donald Trump is "literally Hitler".
Ultimately, the government exists as a unifying force. We all abide by the same laws, and those who break those laws are typically punished. But regardless of who is president, prime minister, monarch, chief, you name it, every single one of those positions is lower than God. Anarchistic societies are all accountable to God. Autocratic, Democratic and Theocratic nations are all accountable to God. Whether all do what is right in their own eyes, or submit to a single legislative body, we will all be judged by the God who gave us life. Will He give us eternal life as well? Only through repentance and faith in Christ. No government can harm us, and no government can save us, on judgment day.