According to physicalist naturalism, there are no gods, ghosts, psychic powers, or supernatural miracles, this world we are now in is all we have, it wasn't intelligently designed for us nor we for it, and nothing and no one is perfect, but physics, technology and human genius can accomplish great things when guided by compassion and careful reflection. All naturalists generally agree with this, but there are naturalists who also believe that certain other things exist besides matter-energy in space-time, which have obscure philosophical names like "epiphenomenal qualia" or "Platonic abstract objects." They propose these things to explain certain aspects of human experience. But I believe all these aspects are really nothing more than the inevitable products of different organizations and arrangements of matter-energy in space-time, so that really, there is nothing else but them.
All naturalists agree that death is the complete end of conscious existence, yet a well-lived life is still wonderful and worthwhile, and we all work to build a better future for those who will survive us, out of love for our fellow human beings and awe at our brief opportunity to be and experience being. We also agree that the only paths to knowledge are empirical investigation and logical understanding, and right and wrong follow from the nature of human beings as conscious, intelligent, creative animals within a universe that is organized in a particular way by blind and dispassionate forces. But naturalists still debate the specifics of moral knowledge and what is best for discovering, achieving, and maintaining human happiness, and they openly accept such discussion and disagreement as a healthy part of the human quest for knowledge and understanding. So any of my moral beliefs may be subject to healthy debate among naturalists.
Finally, naturalists disagree on various obscure metaphysical issues, such as the nature of time and free will. I am a determinist and a compatibilist, which means I believe free will is compatible with the fact that the future is fixed and can have only one outcome. And I believe that all time exists simultaneously, so we only perceive time as moving because of our limited point of view. Other naturalists propose that the future does not exist yet and that time really is created with each passing moment, while some believe that free will is in some sense a special, unpredictable product of the quantum physics of the brain. However, I find that these differences among naturalists do not result in different conclusions about what we can expect or how we should behave, so these disputes are ultimately trivial.
Naturalists also do not have a settled opinion on the origin of the universe, and most agree the answer could be any of a number of different theories that scientists are currently exploring. All naturalists agree that the universe has no intelligent cause and exists of its own accord, but some suspect that the formation and nature of the universe is the inevitable outcome of certain natural and necessary principles, while others--including me--suspect that our universe is a small part of a much larger multiverse, in which every possible configuration has arisen at random. This endless structure either has no beginning, in which case the multiverse is eternal and has always existed, or else it began spontaneously as an inevitable possibility from a completely random potential, a true primordial chaos. On these issues, naturalists await the verdict of science.
Richard Carrier