Some atheists want to have more "debates", but not me. Life is too short. The religious never get it and I refuse to ruin my pleasant day for somebody's entertainment. Here are ways I *avoid* arguing with the religious. The key is not what I say, but what I hear *them* say.
First off, why are we talking? When the subject comes up, I say I'm an atheist. I say it like I say my favorite color is brown; just a fact. I should be able to state my position on gods without having a big discussion about it. I've only got so many breaths on this planet, and I've stopped wasting them.
If someone has questions, then I give the whole thing maybe a minute. I only go longer if there is some proof they are questioning their belief in gods. Anything else is a waste of my day. I stay polite and non-confrontational. The pivotal thing is, I *listen* to them. Here is how I respond, depending on what they say to me.
I think to myself, who are the questions about? If they are questioning gods, then maybe we'll talk. If they are questioning me personally, I won't get sucked in. I exit gracefully, with as few words as possible. Basically, I treat them the way I want to be treated, which means "respectfully".
Belligerent: If they are nasty or preachy, I don't waste my time. I keep the moral high ground and keep my sanity by saying something sincere like, "It sounds like your beliefs give you comfort. I don't see much overlap in our views, so... have a pleasant day." Done. Bye. The belligerent want to get a rise out of me, and I won't give them the satisfaction. I don't argue with crazy people or drunks, either.
Sincerely curious: If they are civil, then I will briefly answer their questions about atheism, for as much time as *I* want to. If they have a question, even one that seems nutty to me, I try to answer it directly, fairly and most of all briefly. If the topic is getting nowhere, I exit respectfully, saying something honest like, "I'm guessing that we are both good people. You believe one thing, and I believe another. I'm comfortable leaving it at that."
Leaning toward atheism: Okay, my heart goes out to these people. They have been manipulated and lied to, and that makes me mad. So I will spend a few minutes with them. I never push it. I answer their questions as simply and directly as possible. Then I exit. My goal is to leave them knowing that atheists are decent, sensible people, and that they are not alone. That's about the best I can do.
The key is listening to what they say. There was a time I thought my clever words were important, but they aren't really. Lately, I get more peace and satisfaction by hearing them, responding intelligently, and getting back to loving my life.