Courtesy of: http://www.revrob.com/
For as long as there have been atheists there have been theists who have tried to claim that atheism is faith, that it takes more faith to not believe in gods than it does to believe in them.
These same antagonists further like to paint atheists as being silly for also believing in things like demons and ghosts.
Unfortunately, some atheists and atheist groups support this misnomer by narrowly defining atheism as only the lack of belief in deities. In reality it is more than that, as the Britannica Concise Encyclopedia points out;
[Atheism is a] critique and denial of metaphysical beliefs in God or divine beings.
Denying the existence of deities is to also deny the existence of all that which can only exist as the result of a deity.
Let’s take ghosts for instance, which are spirits.
Spirits fall under the realm of animism, which is “the worldview that non-human entities (animals, plants, and inanimate objects or phenomena) possess a spiritual essence. Specifically, animism is used in the anthropology of religion as a term for the belief system or cosmology of some indigenous tribal peoples, especially prior to the development and/or infiltration of colonialism and organized religion.”
Anthropologists believe that animism represents the earliest beginnings of the evolution of religion on Earth, and that it probably originated before homo sapiens. Animism may not be an organized religion with a pantheon of gods, but it is still part of an informal egonovist religious belief system that exists today. Because it is religion, faith, and theism, the belief in spirits and horoscopes cannot be congruent with atheism.
As to demons, devils, and angels, they all are forms of deities.
Demons comes from Greek mythology and are later used in Abrahamic religions; in both instances they represent a type of god or demigod. They possess supernatural powers bestowed upon them by a deity. In fact, in the Hebrew Bible sacrifices were offered to powerful demons. In Christianity demons are literally angels.
Devils only exist in dualistic theology where they are in fact a deity that is as powerful as, and is the antithesis to, the creator god.
Angels come from Zoroastrianism where they are a manifestation of God. In Judaism they are literally an aspect of God, and in Christianity they evolved into messengers of God.
In all cases, in order to accept the existence of demons, devils, or angels, one must first accept the premise that at least one deity exists.
Those who seek to intellectually weaken atheism by grouping them in with animists and astrologers and pantheists by claiming that atheists believe in spirits need to be corrected; moreover atheists need to have a stake in the term “atheism,” take ownership and not allow it to include people who are religious, even though their religion does not include a creator deity. Atheism is not only a rejection of deities, it is an outright rejection of theism and metaphysical, faith based beliefs.