I responded with a simple "Nope. Never noticed." If he decided to create an argument about it I'd take him up on his offer.
I've never met someone "immoral" because they were atheists; in fact usually the most immoral people I've had to deal with claimed to believe in god. I was thinking of explaining how mandatory religion usually results in terrible things... But your simple response seems best.
I'd answer much the same. It's a bit of a silly question.
People always look to the past with a selective filter. In this case it's rose-coloured glasses. Sometimes I think people look back to the good ol' days of Americana and see nothing but Leave it to Beaver. I'm pretty sure they still had murder, rape, theft, torture, war, political corruption, fraud, infidelity, sexual impropriety, pedophilia, general violence and brutality (and so on) in pretty much any era you look at. Crime has risen and fallen in many places over the decades, but atheism has mostly just increased. Some of the biggest noticeable increases in atheism (at least in Canada and the US) have come within the past couple of decades, in which case crime has decreased overall. I don't think there's any correlation between the two. Also, if we keep it to America specifically, the most religious states are not necessarily the states with the lowest crime rates.
It's also not like racism, sexual discrimination, and homophobia decrease as we move back into eras of stronger Christian influence. Seems to me, if there was any correlation at all, it would work the other way around. Now, I know that not all Christians see increased gay rights as a sign of increasing morality, but we had homosexuality back in the old days and we have homosexuality now; not much has changed on that front. The major difference is that we have less violence against homosexuals in progressive cultures (where there tends to be more atheists, not less). If a moral person can't get behind less violence, I have to question the value of their ideas on morality.
I'd never use this argument seriously because correlation does not equal causation, it has selective observation written all over it, and it's a matter of opinion, but never the less I might respond with something like this just to make a point on how ridiculous the argument is:
"Ever notice how when God wasn't optional people believed the witch trial burnings, crusades, stoning, oppression of women and minorities, slavery, and things like that where morally right? Ever notice how when God wasn't optional society was savage, ignorant, infested with disease, and things like the dark ages happened? Now, ever notice how slavery and murdering people because they believed something different then you became immoral and equal rights came alone right about when God became optional? Ever notice how society produced things like flight, space travel, improved medicine, cars, the internet, indeed almost everything you use, oh and not to mention doubled your life expectancy, right about the time when God became optional?"
haha, nice one
Need someone to scare the infidels off your lawn again???