Never mind that I'm an antitheist but with a particular demographic any mention of 'Gods will' or any such will instantly loose you any argument.......
May not be too popular a thing to say with many here but it is very much true so it bears mentioning as it is sorta in the same vein as Trump never using 'politician speak' or big words, the whole point of communicating is to get the point across and anything that gets in the way of that just means that you have failed at communicating that point.....
I agree with AZTrumpette1776. It's not a loss if you walk away. A seed has been planted. Whether that seed fell on rock or good soil is yet to be seen, but it was put in place. In time it may take root.
Consider that what you are telling people, saying not to mention God when speaking with others, is a way of 'forcing upon' believers. They don't like that any more than unbelievers. We are all who and what we are. We can only operate within that context. Asking a true believer to quell their belief so that someone else is comfy cozy is akin to telling a man or woman not to be a man or woman.
Besides that, many of us know the power of God's word and discussion of God. It only agitates those who are under the influence of the devil, and that is one sign of success. Someone getting agitated at the mere mention of God.
I understand you identify as an atheist. Most everybody does at one point or another, even many of those who are Christians today. But then something happens, they have an experience that changes their life. You too can have that, if you want it. It's waiting on you, you just have to avail yourself of the gift. Said sincerely, with all humility and sincerity, a little prayer like this will give you the answers you crave.
"God, I don't even believe you exist. It seems to be that you are just the figment of some very fertile imaginations. But just in case I'm wrong, and just in case you actually do exist, I'd like to know. Because I like truth, so I'd like to know the truth. So if you actually do exist, please reveal Yourself to me."
God - the ultimate red pill.