It seems to me that God both transcends the manifest cosmos, being the unformed essence or ground of being from which it all comes, the source, but is also immanent in the cosmos, the cosmos being the incarnation of that transcendent God, the expressed manifest form of that same divine essence. This is also known as panentheism.
I like to think of it in terms of quantum field theory (QFT), where a unified field pervades all spacetime and is the transcendent essence of reality, which is essentially empty and void in itself, but the excitations or fluctuations of that field, the energy of that field, becomes the manifest classical forms or “particles” of the perceived and experienced cosmos. The forms change (the fluctuations fluctuate), but the field itself stays the same (the field is always the same unchanged field). Even though a fluctuation may come and go, the field remains.
QFT treats particles as excited states (also called quanta) of their underlying fields, which are more fundamental than the particles.-“Quantum field theory,” Wikipedia
Or think of it in simpler terms as a body of water. The water itself is the transcendent ground, the essence of its reality, a “sea of glass.” Ripples or waves in the water are the immanent forms of that water, the way the surface of the water is taking shape, is expressing itself, is becoming in time, becoming the various embodiments of the water, the particularizations of the water, the forms of the water.
In Christian theology, I suggest the “Father” is the transcendent nature of reality, the “Son” is the immanent nature of reality. The “Father” is immortal and unchanging, but the “Son” is mortal and is forever changing. But just because the “Father” is transcendent doesn’t make it something apart from the “Son,” but rather it is the essence of the “Son,” it is the source of the “Son,” it is the ground and fundamental reality of the “Son.”
The “Son” is the excitation/fluctuation of the “Father,” the expression of the “Father,” which is why we call it the “Incarnation of God.” The Incarnation is not something separate from God, but God itself taking on particular form, the Word taking on flesh, taking on manifestation, the emanation of God like light rays emanating from the sun. The light rays aren’t something separate from the sun, but are how the sun expresses itself. The “Father” has given birth to its embodied Self in the “Son,” in each and every form of the cosmos.
Thus Jesus says, “The Father is in me,” and “the kingdom of God is within you.” He is pointing to that transcendent essential quality in all manifest creation, the aspect of it which is the substrate from which all things take form, including Jesus and each one of us. It is the universal field which is our common ground, our shared being, our transcendent nature and fundamental identity in this uni-verse.
We are One in that essence, because it is the unified field from which we all are formed and from which we derive our life and embodiment, and Jesus prayed that we could each realize this Oneness in the “Father” (John 17:11, 20-23), that we could directly recognize our transcendent unified nature, our shared being, our divine ground. Paul noted how “in God we live and move and have our being” (Acts 17:28).
God, in its essence, is that unified field, that transcendent ground, that pure consciousness, that substrate of Reality, that unchanging source from which or out of which all things take on form, take shape, derive mind, receive flesh, become embodied in space and time. It is the Transcendent itself that becomes all things immanent, that manifests itself, that becomes each and every thing in the world, including you and me. Even though we appear separate and distinct in our immanent nature, we are One Great Whole in the Transcendent nature of Reality.
And even though our particular immanent forms are temporal and so live and die, the transcendent essence never changes and is thus “immortal.” It has “eternal life.” It is the unchanging nature of the uni-verse and all things in it. We are as ripples on that water, and although the ripples come to an end, the water remains. And all the ripples were was water all along, the water taking on form, energy passing through the water. God lives in us and through us. We are the way God experiences the world, experiences its Self. We are each mirrors of God, the Transcendent looks out through our eyes at its Self. Thus Meister Eckhart notes,
The eye with which I see God is the same with which God sees me. My eye and God’s eye is one eye, and one sight, and one knowledge, and one love.-Meister Eckhart
God is not something else somewhere else, but is our own transcendent nature. God has become us. All things and beings are the way God expresses itself, manifests itself, emanates itself, forms itself, takes on flesh, becomes, lives, breathes, is excited, experiences time, sees itself.
When we can see this transcendent nature in all things, we are seeing as God sees. We are seeing our true Self in all beings and things. We are no longer falsely identified with only the particular form of the body-mind, but we have realized the deeper ground of our communal nature. We can no longer see anything or anyone “out there” as something or someone else, but as simply another manifestation of our deepest Self, the Transcendent ground.
When we can see this way, the Transcendent in the Immanent, then we begin to act in the world in harmony with that perception. We begin to embody things “on Earth (the Immanent) as they are in Heaven (the Transcendent).” We are no longer seemingly divided or separate from the Transcendent, but we are truly incarnating that Transcendent nature in the world. The Immanent begins to take on the qualities of the Transcendent nature more and more, Heaven is brought down to Earth, being a reflection of that nature, including being Peaceful (undisturbed or equanimous), being One (communal and unified, synchronicity connections), being Love (compassion and charity and sacrifice), being Immortal or Eternal (deep time or long-term perspective), being Creative (incarnating new forms of Beauty, Truth, and Goodness).
We can each see this way when we transcend our immanent point of view, the finite subjective localized dualistic nature of our perceptions and thoughts, and return to our essence in consciousness and being. When all the finite and particular qualities and conditioning of mind fall away from consciousness, we can begin to see its transcendent nature, and we are that transcendent nature. When the ripples cease, we see that we are the water. It is not something apart from us. We come to realize our deepest Self as that Transcendent, which is incarnating itself in every particular body-mind form, in the immanent.
This is self-transcendence, this is theosis, this is awakening. We have been “saved” or “liberated” from our attachment to the transient impermanent changing nature of the world and our identification with the dualistic finite form, and have realized our true infinite nondual or at-One ground that is the essence from which it all arises indefinitely.