Do you have other examples, these aren’t really Christian laws. I am a Christian myself, and I support laws providing equal marriage rights for gays. The thing is, the law was already in existence and no one really made any effort to change them until recently. Many Christians oppose those changes, but that’s not so much codifying. I have also met individuals who were atheist and oppose legalizing it because it’s unnatural and wrongly equate it to other forms of sexual behavior that society still strongly frowns on like polygmy, beastiality, and pedophilia. The point is, those are bad arguments against it, but the point is there are non-religious reasons that people oppose it, even if they are dumb reasons.
For abortion, again, there’s a large overlap with Christians and opposing it, but I actually think there’s a stronger non-religious argument, and many of the atheists I’ve met will generally be in favor of some limitations. Obviously the “life begins at conception” is a pretty overwhelmingly religious argument, and you won’t see many non-religious people suggesting a full ban, but I have see arguments put forth for setting a point of life beginning at first heart beat or first measurable brain activity (ftr, both of those are lines I’ve seen proposed by well-known atheists discussing abortion, the latter specifically from Penn Jillette iirc). The whole point is, abortion is fundamentally a rights issue, where those who support banning an abortion at a certain term believe that the unborn is human enough to deserve human rights and thus the right to life trumps the right of the woman over her body, where those who oppose don’t believe it has those rights. And this is why you won’t find many people who support abortions performed the day before the child is due and you also won’t find many people, even many Christians, who would put a full ban even on a 15yo who was raped and elects to abort immediately upon learning that she is. In fact, even among my father and his church, which are pretty straight-forward rightwing Christians, when the issue has come up, they’ve all made some manner of concessions on allowing abortions in some circumstances.
I think my point is that as long as we’re going to be making laws on issues that aren’t purely based on personal or property rights and start treading into territory of establishing morality, you’re going to start seeing religious reasons for it because religious people often appeal to their religious beliefs to establish their moral stance. And that’s why I think we should stay away from trying to legislate right and wrong and just stick to establishing and protecting the rights of people.
As for whether or not it is Christian to do so, I’m not so sure that it’s either. Personally, given my view on the purpose of laws, I don’t think we should be making moral laws of any sort and we should instead try to teach people moral reasoning and to follow it of their own accord. But not everyone would agree with that idea of the purpose of law. Some will believe that the purpose of law is to establish right and wrong and, if that’s the case, then you kind of have to fight to legislate to allow what is right and regulate or ban what is wrong. Of course, I disagree with that view, but I’m not sure that that view is intrinsically religious at all.