But are they correct?
I will admit it certainly appears that way. There is overwhelming evidence that atheists are, at the level of populations, law-abiding, egalitarian, and tolerant. Dr. Phil Zuckerman has found that atheists are less likely than the religious to "harbor ethnocentric, racist, or nationalistic attitudes." In his paper Atheism, Secularlarity, and Well-Being, he concludes that
[a]theism and secularity have many positive correlates, such as higher levels of education and verbal ability, lower levels of prejudice, ethnocentrism, racism, and homophobia, greater support for women’s equality, child-rearing that promotes independent thinking and an absence of corporal punishment, etc. And at the societal level, with the important exception of suicide, states and nations with a higher proportion of secular people fare markedly better than those with a higher proportion of religious people.
How do we know one can't be moral without God?
First, and most importantly, the Bible says so. Boom, QED, end of discussion.
Second, if you insist on further discussion, just look at morals. They're so complex! Atheists tend to claim that these incredibly intricate codes of behavior emerged from human empathy. But no one could possibly accept something so complex coming from something so basic. In fact, for atheists to claim in an intellectually honest way that rules and patterns as complex as morals could emerge from something as basic as the human impulse to empathy, they'd have to show that such emergence is evidenced elsewhere in the entirely naturalistic universe in which they claim to believe.
And that's just not possible. It's not like you see, say, significant changes in butterfly phenotypes based on small changes in genotype. Or even complex patterns emerging from simple rules in binary cell automation. So, clearly, you wouldn't see varied, intricate moral codes emerging from something as straightforward as the capacity to see things from another's perspective. They must, therefore, have come from the God of the Bible -- as the Bible says. QED again.
Third, if you believe (like atheists laughably do) that human characteristics are the product of evolution from an ancestor common to all known life in response to selective pressure, you'd naturally expect to see some form of morality in other social animals -- which is ridiculous. Do you see altruism in insects? Chimpanzees risking or sacrificing their lives for one another, or gibbons voluntarily going hungry when they know that they have to hurt others to eat? Or elephants showing sympathy for the plight of trapped antelope? Despite the evidence of exactly those things, no, you don't. So morality just couldn't have emerged from evolutionarily advantageous traits.
Since there is no secular, naturalistic explanation for human morals, they must be given to humanity by God. Atheists, who reject God, are therefore immoral despite all evidence to the contrary.
So...if atheists are immoral, why do they, on average, behave in moral ways more consistently than the religious?
It has to be Satan making atheists look good to trick people into becoming irreligious, thus earning themselves condemnation to Hell by omnibenevolent God. What other sensible explanation is there?
Thank you, mortals, as always, for reading! I look forward to your thoughts in the comments section.