Imagine you write a small story for fun but then it becomes nearly a religion. It must be a little frustrating for Andy.
These two works express their ideas in very different ways and with very different details, structures, and styles.
That's like saying that Orwell's 1984 is a plagiarism of Yevgeny Zamyatin's We or that Harry Potter is a plagiarism of Ursula K. Le Guin's Wizard of Earthsea.
You are just tackling similar topics. Maybe he took some inspiration from you. You should be proud instead of being butthurt for 15 years.
By the way, the notion that all beings are manifestations of a single consciousness—or that we are all God—is far older than either of you.