Is God the Universe, or Is God Beyond It?
Spinoza was excommunicated for an idea the Svetasvatara taught millennia earlier.
Svetasvatara Upanishad vs Spinoza. God pervades everything like fire hidden in wood, yet also transcends creation.
A Boy Expelled for a Sentence
In July 1656, the Sephardic community of Amsterdam gathered in the synagogue on the Houtgracht and pronounced a herem, a ban, against one of their own. He was twenty three years old. His name was Baruch Spinoza. The wording of the ban has survived, and it is among the harshest ever recorded. Cursed be he by day and cursed by night. Cursed when he lies down and cursed when he rises up. No one was to speak with him. No one was to read anything he wrote. No one was to come within four cubits of him.

The crime, when you strip away the theological wrapping, comes down to a single claim. Spinoza had started saying, or was suspected of saying, that God and Nature were not two things. There was no separate creator standing outside the world, running it from a distance. God was the substance of which the world was an expression. Deus sive natura. God or Nature. The two words point at the same thing.
Two and a half millennia earlier, on the other side of Eurasia, a rishi whose name survives only as the title of his Upanishad had said something unsettlingly similar. And nobody had banned him. He had been celebrated.
The question of this lesson is how two traditions, given roughly the same insight, handled it so differently. And whether the Upanishadic version was actually the same claim at all, or something more careful.
The Svetasvatara's God
The Svetasvatara Upanishad is one of the later principal Upanishads, probably composed somewhere between the fifth and third centuries BCE. It is strange compared to the earlier Upanishads in one important respect: it is personal. Where the Chandogya and the Brihadaranyaka speak of Brahman as an impersonal ground, the Svetasvatara keeps sliding into second person address. Its God has a name. Rudra, who would later be called Shiva. Its God has qualities. Compassionate, fierce, protector, destroyer. Its God has a face, even while the text insists that the face is a concession to human limitations, not the real form.