Prophetic witness and Functionally secular humanist Christianity.

Follow me on this, I will lay out my objections and then what I think you're intending

When you say Christians can't expect the unbeliever to live a Christian life so we ought not tell them to live morally, you are saying Christ has no authority over their lives. Intended or not you are saying he has no place in the public sphere and is not their king. they are judged by the same standard as we are and can benefit from honoring God, moreover Christ is God not just in the church or over it's people but over all sphere's of life and over all people.  Essentially without meaning to you are caving to the culture's definition and narrative.  God is not in the public sphere, self-autonomy is everything and leave us to do what we want. It's the assumption of freedom of religion as simply freedom of worship,yet that's the problem. All of our lives and all of creation is to worship God in honoring him always in all things. Saying otherwise or placing a limit on how Christian's can influence society in their witness to honor God (short of engineering perfection) which transforms the culture is not honoring to God as the arbiter of all truth and the lord of all Creation.

 That surrender has led to the death of Christendom and the society's decline.  We are called to be the salt of the earth.  Don't engineer perfection, you can't.  Do what you're called, and honor God with your voice in all areas of life, saying we can't tell others to honor God is really abbhorent.  In worrying about making us look bad, you leave people in their sin and leave soceity to suffer.  In trying to be kind, you leave people without a witness and society without a restraint.  You can’t watch someone in their depravity and throw your hands up “oh well, let them go” anymore than you can see a loved one digging a knife into their wrists and leave them be because “they don’t think their life is important.

What are you reacting out against?  Is this you're objection to the turn or burn mentalityAmerican Christianity?  It need not be so.  The Prophets of the Old Testament certainly did not, and neither did Christ or the Early Church. We can't conflate poor evangelism that degrades without pointing to God's grace with what is really a Godly influence on soceity and part of  God's call on us to be the salt of the earth.  Take even Jonah in the OT for example who spoke out to a pagan empire, and the other prophets who certainly spoke concerning them.

Where we agree and where the solution is: Evangelism is to be in relationship without neglecting the Grace of God.  This does not negate the duty of Christians to influence society or mean Godly influence isn’t evangelism.

Central tenets to think on

1.      God is the source of all authority and moral law

2.      the Government has moral authority and is instituted by God

3.      Therefore Civil Authority must honor God in it's law or practice, or be judged accordingly.

4.      People saved or unsaved live under God's law and face consequences in this life and the next.

5.      You have influence you can use to the end of increasing the honoring of his authority by the government and private individuals

6.     do it.

From those of seen, and this may not fit you I’ve noticed two things.

You are confusing persons with opinions when you make it personal, this is postmodernism

Or

You are saying the culture can expect or make us act like secular humanists and can do what you are telling us not to while we can’t ask them to live according to Christian moral principles.

Christian’s aren’t somehow the bullies, moreover we are even the minority now.  Applying a double standard like those mentioned is anything but helpful. 

The culture has a consensus by which is legislates, ours is secular humanism. You are not acting as a Christian when you tell Christians to stop advocating social causes or telling nonbelievers not to sin.  You are acting as a secular humanist and absorbing the sinful character of our culture.

The Church always spoke out politically.  Everytime they said Jesus is lord not Caesar, or when they refused and discouraged worship of idols.  Rome was only concerned with politically unity, and Gods were considered local.  To refuse to worship the God’s where you were was considered treason since the God’s were so identified with the state.  Rome saw refusal to worship the God’s as “atheism”, a political charge of treason.  It was believed this failure on the part of Christians would cause the wrath of the God’s to fall on them.  So evangelizing in and of itself was politically charged.

So if you refuse to vote or speak out your Christianity to the culture, you aren’t living as a Christian.  You are living as a secular humanist.

Abraham Kuyper spoke well on the issue.  There are different spheres (in one sense) But
"There is not one square inch in the whole domain of Human existence over which Christ, who is sovereign over all does not cry out MINE!"

Think of it as an interlocking puzzle.  Without Christ in all as lord of all you are missing a piece and unable to see the full picture.