I think in terms of individual salvation, you are correct, HiTech. But in terms of governments, God has the expectation that they ‘servants to do good’(Rom 13:4f). In our nation, God has placed both the culture and the government in the hands of the citizenry, the voters. God expects a wholesome culture, and while He has used some deathly cultures to bring His vengeance on His own and other civilizations in the past, His intent has to always be justice and holiness if He sees them as ‘servants of good’.
There is at best a limited amount they can do. Their mandate comes through Noah, not through Moses or from Christ, and they never pretended to save a single soul. What’s more in Paul’s time prosecutions were private. If someone got murdered, it was up to the family to beg Roman courts for recourse.
Abortion ought to be banned along with other homicide. Forget about the fruits of it, that is arguing about the cherry on top of a rotten cake.
But a society can get SO bad that evangelism is the only civilized way to make its folly stop.