You implicitly asked about the Gnostic experience. Let me say a few words. Modern philosophy, at least since Descartes, has often dabbled in Gnosticism, so you have no doubt read some more or less Gnostic texts, possibly without knowing it. Descartes is not a Gnostic, I believe, but he commits a fundamental philosophical error which paves the way for Gnostic experiences. Consider his famous cogito. He has replaced the human being's participation in the whole (cosmos) with a self-contained Ego. In reading his "Meditations," I keep wanting to ask, "What about reality? What about the whole cosmos? Why are you beginning with yourself as a separate being?" Once he has done that, he can "prove the existence of God," as he purports to do, but he is left with the famous "mind-body" problem. Beginning with the solitary ego, how does one "get out?"
As I read the great philosophers--say, Heracleitos, Plato, Aristotle, Plotinus--I am ever being made aware of human participation in the mysterious whole. That is the ground for philosophizing: the "primary experience of the cosmos," of the essential oneness of all that is, an awareness that precedes the intellect's activity of making the proper distinctions. One of the most moving expressions of this essential oneness I came across some years ago in Plotinus, and when I read it to students, I could not contain tears. It is utterly beautiful. Remind me, please, to share the passage from the Enneads with you. It will "knock your socks off," using your phrase. The lover sees and experiences each and all in every being. That is not Gnostic, but mystical: the mystical experience of essential unity, a kind of "natural mysticism," or "cosmic mysticism," if we can coin that phrase.
Now, as for modern Gnosis, there are many examples, from Mary Baker Eddy (Christian Science [Gnosis]) to Emerson to a my own college-age dabbling, which I grow out of quickly. Consider a few formulations I came up with in my late teens, for they reflect what is probably a Gnostic experience: "I created I" was the earliest at 18. About a year later, I distorted the Platonic symbol of "the beyond" to "I beyond beyond the beyond." Note the break from reality, from common sense. I was playing, but the play was dangerous, and I realized it. The genius of modern Gnosis is without doubt Hegel. In the Phenomenology, he explicitly brings "God" into his self-consciousness. Rather than mystical union, he openly replaces any "divine beyond" with "human self-consciousness." in the long "Preface" to the "Phenomenology," apparently written last, Hegel explicitly rejects philosophy as "love of wisdom," and promises "real wisdom" (wirkliches Wissen) instead. That phrase expresses the move from philosophy as love to philosophy as possession of "wisdom." At the end of the "Phenomenology," after his long exegesis of his experience, Hegel concludes with the "Golgatha of God," of any divine being beyond human self-consciousness. The death of God is achieved speculatively not in a superficial way, but by drawing "all of the divine" into human consciousness. That is a magnificent expression of Gnosticism. Once that is achieved, how does one relate to reality? Hegel replaces man, God, consciousness with his "system of science." Extraordinary achievement.
As you know, Nietzsche rejected any attempt to provide a "system," and helped to reclaim genuine philosophy as anti-system, and for that I praise him highly. He knew that reality could not be reduced to a "system of science." But Nietzsche had his own games to play. As you probably know, his "philosophizing" radically cut him off from human contact, and he became utterly lonely and isolated. I cannot read Nietzsche without feeling his anguish, and wanting to befriend him. I love him, but he went down one huge "rabbit hole" to the point where he could not return. That is how I read his breakdown: it indexed a spiritual-mental collapse, not merely physical disease. In reading his works, I can see the extreme breakdown coming, as he divorces himself from one part of reality after another. Nietzsche is a delight to read, a first-rate intellect, but painful to read, too, when one sees what he does to himself. But in the process, he throws much light on modern biases, such as his attack on democracy and "the herd mentality," and so on. He would have detested the Nazi movement, but they used him, as you know, by bowdlerizing his works.
Now for a sample from "Thus spake Zarathustra," from the poetic "Night Song." I was mistaken. It is in Book II (section 9) of Zarathustra, not Book III. I type this to show you what is typical, or perhaps essential, in the Gnostic experience. Using Kaufman's well-known translation:
The Night Song
Night has come; now all fountains speak more loudly. And my soul too is a fountain. Night has come; only now all the songs of loves awaken. And my soul too is the song of a lover. Something unstilled, unstillable is within me; it wants to be voiced. A craving for love is within me; it speaks the language of love. Light am I; ah, that I were night! But this is my loneliness, that I am girt with light. Ah, that I were dark and nocturnal! How I would suck at the breasts of light! And even you would I bless, you little sparkling stars and glowworms up there; and be overjoyed with your gifts of light. But I live in my own light; I drink back into myself the flames that break out of me. I do not know the happiness of those who receive, and I have often dreamed that even stealing must be more blessed than receiving. This is my poverty, that my hand never rests from giving... Oh, darkening of my sun! Oh, craving to crave! Oh, ravenous hunger in satiation. They receive from me; but do I touch their souls?...I should like to hurt those for whom I shine; I should like to rob those to whom I give; thus do I hunger for malice. Such revenge my fullness plots; such spite wells up out of my loneliness. My happiness in giving died in giving; my virtue tired of itself in its overflow.... Alas, ice is all around me, my hand is burned by the icy.
Alas, thirst is within me that languishes after your thirst.
Night has come: alas, that I must be light! And thirst for the nocturnal. And loneliness.
Night has come: now my craving breaks out of my like a well; to speak I crave.
Night has come; now all fountains speak more loudly. And my soul too is a fountain.
Night has come; now all the songs of lovers awaken. And my soul too is the song of a lover.
Thus sang Zarathustra.