This section encompasses Jewish folklore, The Bible and The Quran, plus deuterocanon.
Let us begin with a preface: Nobody, with the possible exception of Hinduism and Buddhism, does the supernatural Eldritch Entity quite like the Western world’s favourite religious tradition. The concept of monotheism, combined with the Platonic Theory of Forms (a direct and heavy influence on modern “Pauline” Christianity and a less direct influence on both Rabbinic Judaism and Islam) and taken to both ideas’ extremes is a fantastically alien experience. All the major Abrahamic religions and apologetics emphasize how the true form of God (and all the other “higher” celestial beings, but especially God) is beyond logic, causality, physics and comprehension of the human mind, because of His Transcendent nature, and so, atheists trying to apply logic to these entities are just trying to exercise in complete futility. So, with that said let us truly start:
He was an All-in-One and One-in-All of limitless being and self — not merely a thing of one Space-Time continuum, but allied to the ultimate animating essence of existence’s whole unbounded sweep — the last, utter sweep which has no confines and which outreaches fancy and mathematics alike. It was perhaps that which the religion and philosophy of Christianity of earth have referred to indirectly by the common noun God, and which has been a deity under other names; that which the Muslims worship as Allah, and by which the Rabbis of Judaism whisper by a cryptic arcane Tetragrammaton that only appears in Latin transliteration as “YHVH”. Most people think it would have been pronounced “Jehovah”, “Yahowah” or “Yahweh”, but no one can really be sure. It was theorized that properly pronouncing the name of God will only result in insanity, hence why it is a blasphemy in Ancient Jewish folklore to attempt it.
The “elder” we represent in our art is, in fact, just one of many forms and may in fact have both female and male traits. In fact God existing on such a vaster plane of existence than humanity might think of a mortal form as laughably inconvenient and beneath the dignity of His Omnipotent status. The Bible rarely even gives any description that could let one picture a physical appearance, typically calling God a spirit, and the few times it does it’s made clear this is only a form he chose for that occasion. In Kings 19:12 he comes as a simple whisper in the wind but in Ezekiel 1:27…
“…[H]igh above on the throne was a figure like that of a man. I saw that from what appeared to be his waist up he looked like glowing metal, as if full of fire, and that from there down he looked like fire; and brilliant light surrounded him. Like the appearance of a rainbow in the clouds on a rainy day, so was the radiance around him. This was the appearance of the likeness of the glory of the Lord.”
…and even he shows himself in this form and speaks through it to Ezekiel his spirit is not limited to it and continues on with other tasks.
He can never die and could likely claim that it had been around since the dawn of eternity, and with strange aeons even Death itself will die and be thrown into Hell. He has existed before time itself began and will exist long after the fabric of space and time itself has died, is literally the beginning and the end of all things and thus has seen the beginning of history, and will usher in the end of history as well. On top of that, He never changes and is the same yesterday, today, tomorrow and forever, despite changing His ideas every chapter and then, and… My brain already hurts from the potential self-contradictory paradoxes this entity could incur, but that’s actually just a very tiny part of theological wild mass guessing on what the nature of God really is. There’s a reason why some people can only sum Him and all the contradicting descriptions of Him up as “God works in mysterious ways”.
Basically, Cthulhu is a cute little cutie compared to God. A related postulation is that His true form will Mind Rape you with its sheer eldritch glory and completely annihilate free will forever. Worst of all, He completely controls our destiny whether we like it or not. He literally did everything. Unlike other Outer Gods, however, God at least provides love as long as you worship and revere Him, and He has the decency to take A Form You Are Comfortable With we all love named Jesus (then again, Outer Gods communicate with us through Nyarlathotep and considering Jesus’ true form in Revelation…), but then again, He can and will perform many nasty acts like smite and punish thee for the tiniest amounts of Thought Crime. He might be forgiving, but if anybody else, even the most powerful of the Angels, are stupid enough to think of themselves Above the Most High, then he’s definitely screwed.
His omnipotence, combined with pretty extreme measures when dealing with heresy, still makes Him a force to be reckoned with. He’s overall trying to be nice, but He is harsh. Even our best theologians and philosophers don’t help in describing His mindscrew-like nature, with interpretations so contradicting it ends up inspiring War, Madness and Terror on both sides.
Islam takes this bit particularly seriously; being the omnipotent, omnipresent being who created the Universe, it is forbidden to portray Him in pictures, partly, at least, because You Cannot Grasp the True Form.note
In fact, just looking at Him causes you to explode. The Kabbalist philosophy is that a Seraph burns by consequence of being smart enough to understand the most high’s glory better than anything else.