Fist off
thank you for asking. Its rather refreshing.
Second
you ask a very difficult question.
While Pagans do not have a rigid set of dogmatic beliefs that make one a Pagan there is a general set of beliefs that most Pagans accept.
Views of the Divine:
Most Pagans are simultaneously Polytheistic (believing in many individual Gods and Goddesses) dualistic (believing in a matched pair of deities taking the form of the God and the Goddess and monotheistic (believing in a single unifying Divine being) no it is not a contradiction. Pagans tend to view the individual Gods and Goddesses as personas, aspects or masks of the single ultimate Divine. While theoretically it is possible to worship the ultimate Divine in practice it is sort of like swimming across the Pacific ocean. A single unifying ultimate Divine being is by definition an abstract and rather impersonal concept, I am sure you are aware that it is rather difficult to form a personal relationship with an abstract and largely impersonal concept. The individual Gods and Goddess are a means by which the Divine and Humans can form interpersonal connections. There existence is of course by the will of the Divine and the form of the individual Gods and Goddesses come from the collective unconscious of those who worship. (this would explain why the Christian God a God of middle eastern origin appears as an elderly man of northern European decent)
NeoPagans in general believe is a multitude of individual personal deities usually passed on pre-Christian pantheons such as the ancient Greek Pantheon, the Norse Pantheon, the Celtic and the Egyptian pantheon are popular cultural sources but these by no means limit the possibilities. While belief in a multitude of deities is widespread individuals usually develop personal relationships with only a few of these deities. Pagans view all Gods and Goddesses (including the Christian God) as equal and valid, but believing in the existence of a particular God/Goddess does not equate to worship.
This belief in a multitude of Gods and Goddess united as part of a single divine being allows Pagans to be inclusive in their religious beliefs. Since ALL Gods and Goddesses are considered to be part of the Divine all Gods and Goddesses are legitimate and the religions around these individuals deities are legitimate and acceptable paths to the Divine for any and all who practice. As such Pagans reject the view that there is a single path to the Divine (after all
how could an infinite and Divine being have but a single path to it? Such a Divine being is without limitation and it makes no sense why there would be a limitation on an unlimited being.) this allows Pagans worshiping different Gods and Goddesses to worship together without conflict. This view of the Divine also allows Pagans to participate in other religions as we understand that religion and the ceremonies of a particular religion are human construction and what is important is ones personal relationship with he Divine.
Panentheism:
Panentheism is the belief that the Universe is part of and contained within the Divine but not identical to the Divine as in pantheism. Thus the Divine is both immanent (present in the world) and transcendent (above or beyond the world).
Popular NeoPagan art depicts the Divine as a pregnant woman who is carrying the Earth in her womb. It is an apt metaphor in that the Earth (universe) is dependant on the Divine for its existence but is itself differentiated from the Divine itself.
The Universe is not seen as created ex-nilo (out of nothing) but rather out of the Divine itself. Therefore the Universe (and all in it) is not considered to be divine rather it is considered to be sacred. Thus the Universe and all things in it have intrinsic value because they are part of the Divine itself. This concept forms an important facet of NeoPagan ethics.
Animism:
Pagans believe that the Divine manifests throughout everything, nothing is merely a thing or an object. Everything is an expression of the Divine. Everything has a soul, (or more specifically all things are imbued with the spirit of the Divine) not just humans
Contextual ethics:
Usually Pagans are accused of having relativistic ethics but this is simply false. Pagan ethics are contextual in nature and based on the concept of acting in the best interest of the other. (please understand that forcing ones worldview onto others is NOT acting in the best interest of others but an act designed to glorify the self).
NeoPagan ethics are individual and based on the unique situations that one finds oneself in. The day to day basis for making moral decisions is based on the rede and the three fold law. The rede (rede literally translates as a piece of good advice) has a long and convoluted history, modern usage comes for the last lines of a work written by Doreen Valentine An it harm none, do as thou will Wiccans follow this piece of good advice knowing full well that it is impossible to achieve such a state. The very act of breathing harms countless micro-organisms. All actions have consequences and there is now ay to see all of the possible consequences of our individual actions. The idea is not to achieve such perfection but to become aware of the consequences of ones actions (and inactions) and attempt to make the best possible choice given the set of circumstances on is in.
The three fold law is in fact not a law so much as an observation of the consequences of ones actions. The biblical equivalent is as you sow, so shall ye reap. Your actions come back to you and there is no way to avoid the consequences of your decisions so you need to be prepared to accept and deal with the consequences of your actions.
There are no authoritarian codes of conduct, no list of commandments or rules. One is expected to make the best possible decision one can in any given situation.
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Value of humans, non-humans and the inanimate comes form our Panentheistic world view, the fact that we are all part of the Divine itself gives all things intrinsic and equal value.
Sin:
Sin is a strange and utterly foreign concept to Pagans in both of sins forms: SIN meaning willful separation from God and sin meaning disobedience or disregard for specific rules of an authoritarian moral code.
Sin (lower case) is a conceptual impossibility for pagans since there is a complete lack of Divinely written authoritarian codes of conduct it is impossible to sin. True there is no lack of human created moral codes that claim to have been written by the Divine but these belong to the mythology of their respective religions.
SIN (upper case) is even strange and equally impossible. It is after all impossible to separate oneself form the Divine, it simply cannot be done. Nor can one live without the Divine presence, ones beliefs about living separate from the Divine are beside the point.
The eternal now:
Christians tend to view time as linear, time began at a specific point and runs in one direction to the present and at some undefined point in the future time will end. NeoPagans view time as cyclical. Time is a series of repeating cycles. Seasons change but winter always returns. The sun sets and will do so again tomorrow. To be born is to die. Rather than view time as a single straight line NeoPagans imagine time as spiral, always returning to the same yet not identical place.
A significant consequence in the different views of time is Christians focus on the past and past events. Pagans on the other hand tend to live in and focus on the present.
Evil:
Pagans do not believe in evil much less the personification of evil in the form of Satan or the devil. We generally do not see suffering as evidence that there is something fundamentally wrong with the world. The world is not a playing field for the struggles between good and evil. The only evil one can find are the hurtful things humans do to each other and to other creatures of this world (and sadly the vast majority of these hurtful things are done in the name of religion). Death is an intrinsic part of life and as such is neither evil or something to be feared. The same can be said for disease, suffering and sadness. There are things in the universe well worth avoiding, some of them quite terrifying or lethal but that does not make them evil.
Afterlife:
Generally Pagans believe in both reincarnation and a spiritual realm of the dead. This spiritual realm is popularly called the Summerland and is considered to be a happy place where souls rest and reflect on the past lives and the future ones. There is not generally a belief in cross species incarnations, human souls tend to be reborn in humans and canine souls tend to be reborn as dogs. The soul is believed to preexist the body and is considered to be part of the Divine consciousness and upon death it is to that same divine conscious that the soul returns
I hope this helped you a little bit.
Please dont stop asking questions, it is the only way to actually learn about the beliefs of others.