Standing alone, atheism is a disagreement. Atheists do not agree that God exists. We are not absolutely certain that there is no God, but then again, we cannot know with 100% certainty that Santa Claus is not real. We think that God, like Santa Claus, is very likely a fiction.
A rejection of God is only part of the story. Many atheists, certainly most of the atheists you encounter in academic and intellectual environments, reject all supernatural claims. We think there are no gods or demons, no angels or jinn, no souls, no life after death, no ancestral spirits, no karma, no psychic powers or occult influences, no magic or witchcraft, no prophets, no revelations, no cosmic justice, and no purpose structuring the universe. We usually think this is true the same way we think that no macroscopic information in the universe today can be transmitted faster than the speed of light. The evidence, as best as we can tell, rules out communication faster than light. And our evidence, as best as we can read it, makes the most sense without supernatural agents. Naturalistic atheists think that this is a bottom-up world, where everything we know is realized by natural, fundamentally purposeless processes.
Now, when people want to know more about atheism, they usually are not looking for a science lecture. Since our culture closely associates morality with religion, their first question is more likely to involve morality. Among naturalistic atheists, many are, broadly speaking, secular humanists. We have thisworldly reasons to help one another, to not cheat on our taxes, to not kick the dog. You will find us to be decent neighbors, even though we do not believe that decency is guaranteed to ultimately prevail. We can be dependable political allies, even if we understand good and evil in terms of human interests rather than divine commandments. Still, we are different. We tend to be less conservative than the religious, more at home in the modern world. We live with less certainty, with more moral gray areas.
Since neither skeptics nor believers are going away, we might as well figure out how to live together. This should not be too difficult. Atheists usually dislike more fundamentalist faiths, but do not object to belief as a personal matter. We strongly support a secular political life, defending principles such as separation of church and state. If the religious do not insist on making doubt a public liability, there is no reason that our disagreement about God should not be a friendly disagreement.
(Later in the month, I’ll be giving a 5-minute presentation on atheism as part of a panel discussion on campus. I thought I’d jot down what I’d like to say…)