Religion
In reply to the discussion: Where do you atheists get your morals? [View all]Virtually all atheists will admit, with Dawkins, that they cannot be 100% certain that there is no god; their only certainty is that they do not believe in a deity. Of course it can be a conclusion as well but it remains the principle that guides the actions of those who follow it. An example is that there is no deity to accept the blame for my actions therefore I must be prepared to take personal responsibility for what I do.
You next assume that I do not believe that there are religions, unfortunately there are. Religions set themselves up as judges of moral behaviour but, unlike you, I do not think that they are or should be the sole judges of what is moral and what is not. This last is because many, if not all, religions teach that which is immoral - as I demonstrated in the case of Christianity.
Next, no religion will say that it is the source of morality but some, like the Abrahamic faiths, claim that all morality has its source in the godhead. Pretty obviously a source of morality as tainted as the deity in which you have faith cannot be the fount from which morality flows.