When we say "The cosmos is divine"... we are talking about our own emotional responses to the real universe and the natural earth.
When we say "That tree is beautiful", we are not saying anything about the tree in itself, but about the way we feel we must respond to the tree. We are talking about the relationship between us and the tree. In the same way, if we say "The universe is divine", we are making a statement about the way our senses and our emotions force us to respond to the overwhelming mystery and power that surrounds us. We are saying this: We are part of the universe. Our earth was created from the universe and will one day be reabsorbed into the universe.
We are made up of the same matter as the universe. We are not in exile here: we are at home. It is here and nowhere else that we can see the divine face-to-face. If we erect barriers in our imagination - if we believe our real home is not here but in a land that lies beyond death - if we believe that the divine is found only in old books, or old buildings, or inside our head, then we will see this real, vibrant, luminous world as if through a glass darkly.
The universe creates us, preserves us, destroys us. It is deep and old beyond our ability to reach with our senses. It is beautiful beyond our ability to describe in words. It is complex beyond our ability to fully grasp in science. We must relate to the universe with humility, awe, reverence, celebration and the search for deeper understanding - in other words, in many of the ways that believers relate to their God.
When we say "The earth is sacred"... we are saying this: We are part of nature. Nature made us and at our death we will be reabsorbed into nature. We are at home in nature and in our bodies. This is where we belong; this is where we must find and make our paradise, not in some spirit world on the other side of the grave. If nature is the only paradise, then separation from nature is the only hell. When we destroy nature, we create hell on earth for other species and for ourselves.
Nature is our mother, our home, our security, our peace, our past and our future. We should treat natural things and habitats as believers treat their temples and shrines, as sacred - to be revered and preserved in all their intricate and fragile beauty...
When theists worship gods, they unknowingly worship the cosmos. If they believe that God is also present in nature and the universe, they will perceive a part of the glory of Being, yet still they will attribute this glory to something beyond Being. Still they will fail to connect with nature and the universe in the deep intense way that pantheism makes possible.
But theists who believe that God is separate from the universe separate themselves from Reality. They turn their deepest attention away from the real divinity before their eyes, towards an imaginary divinity inside their head. It veils Reality like a thick mist. It turns believers into sleepwalkers.