Okay, I will respond beginning where you differ: Apparently you conclude/infer that Christians are NOT "to use civil power
to enforce specifically Christian moral conclusions on unbelievers".
Just who do you suppose IS supposed to use civil power?
Just WHAT morality do you infer is supposed to be enforced?
On just WHOM do you think would need to have moral behavior enforced?
The problem of having wrong interpretations is made WORSE when the HS is not supplying the missing links.
Appealing/returning to the text does not solve that problem when people are not truthseekers.
Textual evidence is only as strong as the inferencers make it.
Your inference/harmonization divorces rulers from Christians, which is a big mistake per what I infer from Rom. 13:1-5.
The church should bear witness to the whole Christ, both the sword and the love, because as you noted, the NT teaches both.
What you do not see is that passage merges those missions by saying godly rulers are not a threat to moral citizens. (Myopia?)
What you are not arguing is that YOUR inference is more likely than mine.
BOTH of our opinions remain inferences, requiring both right understanding of the text and divine logic guided by the Spirit
in order to connect the dots correctly.
I agree that both of our positions involve inference.
Where I think we disagree is over which inference is actually supported by the text.
You ask who should use civil power.
My answer is: the civil rulers God has ordained to bear the sword (Rom. 13:1-5).
The fact that a ruler may be a Christian does not automatically merge the mission of the state and the mission of the church.
Romans 13 says rulers punish evil and reward good. I agree.
What it does
not say is that Christians, as Christians, are instructed to use the machinery of civil government to enforce specifically Christian doctrines on those outside the faith.
You say my view divorces rulers from Christians.
I don't think that's accurate.
A Christian may certainly serve as a ruler.
The question is whether the New Testament assigns the church the task of governing society or assigns the church the task of making disciples. The latter is stated explicitly. The former is not.
As for Romans 13, saying that godly rulers are not a terror to good conduct does not merge the missions.
It simply describes the proper function of government.
I also agree that appealing to the Holy Spirit is important.
My concern is that the Spirit will not contradict the text He inspired.
Therefore, when two believers claim opposing inferences are Spirit-led, we still have to test the inference against what is actually written.
So yes, both of our views involve harmonization.
The remaining question is not whether we connect the dots, but whether the specific connection being proposed can be demonstrated from the apostolic instruction itself. That's still the point I'm pressing.