Earlier quoted context omitted.
You're moving the argument too far. As complex societies developed without a moralizing god, religion is not necessary for morality. You can't use this to then say religion is unnecessary, as nobody has said morality is the only reason for religion. Even today, many religious people will say that atheists are incapable of having morals. This is evidence showing that claim is ridiculous, not an attack on religion.
Atheists can certainly act morally, and many do. But I would say that atheists don't have a basis for having morals. dictionary.com says that morals have to do with "right conduct". But in atheism, there is nothing with the authority to give you a definition of "right". There's nothing absolute in the way that, say, the Christian God is absolute, except the universe, and the universe doesn't tell you what right condu…
Suppose there is a god that has defined right and wrong, how has this knowledge been passed to mankind? If it is innate, then an atheist would have the same morals as everyone. If there is no knowledge given, then an atheist's innate sense of moral right is as likely to be correct than any others.
The third option is that they come from religious texts, in which case you are picking a standard as it matches your sense of what is right. Even if the morals are absolute, our inability to accurately find them makes them indistinguishable from an atheist standard.