This is a summary of the terms used as "Belief Types" in the Comparison of Religions – Quick Reference Guide.
MonotheismMonotheism is a religion that acknowledges the existence of only one god. Monotheists may or may not also acknowledge the existence of lesser spiritual beings, such as angels, demons and spirits, but they are always subordinate to the single god and are not deserving of the worship reserved for that god.
When people think of monotheistic religions, they generally think of Judaism, Christianity and Islam: the three major Judeo-Christian religions. There are, however, a number of additional monotheistic religions. Some of these are also Judeo-Christian religions or at least influenced by them, such as Vodou, the Rastafari Movement, and the Baha'i Faith. Others exist independently, such as Zoroastrianism and Eckankar.
A religion that demands the honoring of a single specific god but acknowledges the existence of others is known as a henotheism. No such religion is currently listed on the Quick Reference Guide.
Dualism Dualism recognizes the existence of exactly two deities, which represent opposing forces. Believers only honor one as deserving of worship, generally associating them with goodness, order, sanctity and spirituality, while the other is rejected as a being of evil, corruption and/or materiality.
Religions such as Christianity and Zoroastrianism recognize a single god, but they also acknowledge a being of corruption, which should be rejected. However, in neither case is the corrupted being a god, but rather something of lesser status. As such, these faiths are not considered dualistic, but are instead monotheisms. The theological differences can be significant between the two views.
PolytheismPolytheism is any religion that honors more than one god, but not in a dualistic relationship. Most polytheistic religions acknowledge dozens, hundreds, thousands or even millions of deities. That does not mean, however, that a polytheist regularly worships all such deities. Rather, they approach the gods as needed, and may have one or several toward whom they feel particularly close.
Polytheistic gods are generally not omnipotent, unlike monotheistic gods. Rather, each god has his or her own spheres of influence or interest.
AtheisticAn atheistic religion is one that expressly states that there are no divine beings. (The lack of supernatural beings in general is also commonly accepted, but is not specifically inherent in the term.)
The Raelian Movement is an actively atheistic movement, as formal acceptance into the religion involves a renouncing of previous religions and the embracing of the fact that there are no gods. Instead, the creation of the human race is credited to advanced life forms living beyond the planet Earth, and it is their wishes, not the wishes of a supernatural being, which we should endeavor to embrace for the betterment of humanity.
LaVeyan Satanism is commonly described as atheistic Satanism, although there's no formal declaration of such, and some of these Satanists may describe themselves as agnostic.
Non-TheisticA non-theistic religion does not center upon the existence of any deities, but it does not deny their existence either. As such, members can easily be a collection of atheists, agnostics and theists.
Theist believers often integrate their beliefs in a deity or deities with the non-theistic religion, rather than dealing with the two beliefs as separate entities. For example, Unitarian Universalism stresses many humanistic beliefs. A theistic Unitarian Universalist can easily understand these values as being the wish of God or being part of God's design.
Personal Development MovementPersonal Development Movements encompass a very wide range of beliefs and practices, many of which are not distinctly religious, although some are. Personal Development Movements primarily focus on techniques for believers to better themselves in some way. When these techniques have a spiritual or supernatural component to their understanding, they are frequently categorized as religious.
Some people look to Personal Development Movements to fix things specifically within themselves such as health, ability or intelligence. They may also be looking to improve their connection with the world, to attract more positive influences and to drive out negative ones. They may be looking for very tangible results, such as wealth and success, but they understand that some sort of change needs to occur to himself or herself in order for these desires to manifest.