Atheism

There's no point trying to change the mind of someone who actively goes out and argues for why Christianity is true when there's far more fence-sitters you could talk to.

You're not wrong. but read that line again. "I suppose it's improper to..."

I also contend it's not my duty, obligation, or place to try and change anyone. as long as they do their thing where it doesn't impact me, then their beliefs are none of my business.

I disagree that it’s important. First off, I’m not a cleric or priest, there is no need or obligation for me to propagate my lack of religion. I feel zero responsibility for providing spiritual guidance (for lack of a better phrase,) to some hypothetical randos that may or may not be questioning their faith.

For one thing those randos lack any form of trust, anything aside the most basic, is unlikely to alter anything- they’re just gonna have to sort through it on their own.

For another, these sorts of debates are rather unlikely to happen in a venue with persuadable randos. No apologist sets up a conversation like this in a venue they don’t have at least some control, and those in their flock that are persuadable will unlikely to be there. Either one is the sock. puppet there to feed questions for them to “answer”; or one is there to prove the point by being the Awful Atheist. Either way, it’s a set up.

and in more personal conversation; that’s unlikely to happen where you can be randomly overheard. If the person starts arguing their point, rather than listening to what you have to say; then they haven’t given you the respect of accepting they might be wrong.

In short, you’re not gonna persuade that person; they’re not going to persuade you, and it devolves into name calling and wanting to prove the other wrong. (Or someone walks away before that happens.)

Any one who’s generally trying to understand your worldview, or your beliefs, aren’t going to be trying to change them. They’re simply asking questions to understand; which is an incredibly different sort of conversation.

They might ask about morality, for example, but there isn’t any of the “but morality must come from god” crap.

Ethics and morality all stem from our social nature. Morality is part of our cultural understanding- and while we might all have different takes on it, generally, what is right or wrong stems from that shared understanding; (to the inevitable: that shared understanding is with those around you. Not necessarily society writ large.)