PantheismPage3

Does pantheism believe that all things are one?
Spinoza, the first modern pantheist, believed that there was only one substance in the universe, and that was God. This position is known as substantial monism.
Most modern pantheists are monists in the sense that they believe there is only one type of substance - matter - rather than two different and distinct types, spirit and matter. They believe that all individual things have a common origin with humans, and are closely interlinked and interdependent in many ways. They and we interconnect through social systems and ecosystems and the greater system of Gaia, as well as through gravity and the universe-wide spread of signals and impacts.
However few modern pantheists would agree with Spinoza's extreme form of monism. Anyone with eyes can see that matter in the universe is arranged into distinct individual things: galaxies, stars, planets, trees, people. This diversity is an essential part of the beauty of nature and the night sky. Without diversity everything would be drably monotonous.
Attempts to deny diversity usually end up in claiming that the visible world is mere illusion. Scientific pantheism believes the universe is vibrantly real.
So things are one in some senses, and many in other senses. They are linked in some senses, and separate in others. Anyone who claims that things are totally united, or totally separate, is flying in the face of everyday experience and of scientific evidence.

Does pantheism believe that humans are one with nature and the cosmos?
Yes, there is a fundamental underlying unity. Humans are made of the same substance as the rest of the universe. We don't have any magic spiritual ingredient just for ourselves.
We developed as part of nature, and remain part of local and global ecosystems.
However, humans do have consciousness, and that can be a blessing or a curse. The conscious mind evolved to help survival, and it can help us to relate to nature and the universe through love, appreciation, study and action.
But consciousness also means awareness of one's own individuality, so it can also give us a misleading sense of separation from and radical difference from the world. Our ideas can also develop out of tune with reality and with nature.
So it is important not just to state that there is a unity, but to learn to perceive that unity, to understand it, and to act upon it.

If God is everything, then surely all actions are God's actions, and there is no distinction between right and wrong?
This is a misconceived Christian criticism of pantheism. Certainly a few sects of Pantheists (like Tantric Buddhists and some pantheistic Christian heresies have believed this.
But remember that pantheism does not say that "God is everything", but rather that the universe is divine. Within that overall divinity, it is possible for intelligent species or individuals to become separated from the divinity and to act in conflict with it, by harming nature or other people.
Modern pantheists are not amoral. They have very strong ideas about right and wrong in relation to environmental ethics and social justice. They would consider environmentally destructive or unjust and oppressive actions as "evil."

Does pantheism believe that everything is predetermined and there is no free will?
Some pantheists, like Spinoza and Einstein, have believed this. The Stoics believed in a divine providence, as if the universe had a plan for its own evolution.
But there is no logical link between pantheism and determinism. Many pantheists have not been determinists, and many believe in free will.
Scientific pantheism does not believe in determinism. Of course no-one could prove conclusively that things were not predetermined - the future may already exist, and we may be simply moving into it. In that case space time would be like a monolithic, rigid block with no freedom of movement and no room for free will.
But there is no scientific evidence to suggest this. Indeed two crucial branches of modern science strongly suggest the contrary.
Quantum physics suggests that although the overall pattern of sub-atomic events is predictable, the outcome of any particular event is unpredictable and seems to be undetermined - at least by any laws we are presently aware of.
The science of chaos shows that very small differences in the present can make enormous differences in the future - a butterfly flapping its wings in China may cause a cyclone in the Bay of Bengal. Therefore it would be possible for a tiny undetermined sub-atomic event today to influence the future on a very large scale, just as minute quantum fluctuations in the early universe may have influenced events on the scale of galactic clusters today.
Scientific pantheism also believes in free will. Our actions are usually shaped by our drives and the belief systems we have built up over our lives. But we are also free to change our ideas, and humans often do so. We can also learn to resist our selfish drives. Everyone has examples from their own lives of agonizing between alternative decisions that were very finely balanced.
The future is undetermined. The future of life on earth is ours to make - or unmake.