God clearly can't exist because an omnipotent, omniscient, and just God is a paradox already. Omnipotence and omniscience means that God, if they exist, would have full control of every moment of the universe (even if they only "acted" initially). Some (I'd argue nearly all) people suffer for reasons out of their control. Only deserved suffering is just. Since undeserved suffering exists then God cannot exist (at least omniscient, omnipotent, and just - as we understand those terms). God could be an omniscient, omnipotent asshole or sadist... God could be omniscient and just (aka the martyr God who knows of all suffering but is powerless to prevent it)... or God could be omnipotent and just (aka the naive God who you could liken to a developer running around desperately trying to spot patch problems and just making things worse).
Alternatively, by omnipotent maybe the scriptures are just hyping them up - "God is so fucking buff - this one time they lifted up this rock that was like this big. Fucking amazing."
Ah, the Epicurean Trilemma. This was my answer too. Weirdly attributed to a guy from before monotheism was the predominant belief.
Alternatively, by omnipotent maybe the scriptures are just hyping them up
The scriptures don't use that word, and it's notable because the Old Testament didn't believe that to be the case, either. Early Israelites were henotheistic. They believed other gods might exist (hence the need for "thou shalt have no other gods before me"), but only worshipped the one. When multiple gods exist, it is by definition necessary that they cannot be omnipotent.
It's pretty clear that he is not meant to be omnibenevolent either. The god of the Tanakh is wrathful. Christians later reinterpreted him as omnibenevolent, but this was clearly not the authors' intent. I believe Jewish scholars still don't think he's omnibenevolent today.
Religious scholars have come up with a number of other proposed solutions to the trilemma. Ones involving free will are quite popular, though not the only ones. I have yet to find any argument that is remotely convincing, however. Saying "free will" just means god either cannot or chooses not to enable people to have a form of free will that does not involve them desiring to do evil. It also ignores the very many evils not created by human action. Child cancer, earthquakes, drought-induced famine (today humans have the technological ability to solve this last one and might simply choose not to, but historically it has been an insurmountable problem not caused by human free will).
I recommend you read "Religion of the Apostles" by Stephen De Young. He explains the common misconceptions of the early Israelite beliefs. The "Gods" are lesser divine beings that were meant to protect the 70 tribes after the Tower of Babel fell. The deities rebelled against God and led the nations astray and were worshipped. The tribe of Israel worshipped the God of "Most high" which is the one true God above all divine beings. So they aren't henotheistic because there is only one God. The term "Gods" was used because they were divine beings but they were created whereas God the Father is not. Everything proceeds from him.
A great podcast that explains evil and suffering is "Whole Counsel of God" with the same guy. In short, suffering is unavoidable because man falls from Eden after sinning and the consequence of sin is death. Making death the consequence is a mercy because man can become sanctified during his life and through death re-enter the kingdom of God. Consequently suffering draws people closer to God than anything else.
I'm not a theologian and wrote this on my phone but that's my quick recap. The book is way more thorough of course.
I haven't read the book, but I did some reading about it, and it seems like it's come against some significant criticism for being poor academics and its author criticised for presenting his own one academic idea as a fact.
So while it's certainly interesting to hear his theory from your summary of it, and to learn that there are competing theories out there, I don't think it's going to change my understanding of where scholars more broadly stand on it. The fact that I can't really find anyone talking about de Young's interpretation of early Israelite monolatry (which I've just realised is possibly a more accurate term than henotheism, though the lines between the two are blurred) concerns me from that perspective. Which is not to say that's it's necessarily wrong. It especially could have been a phase they went through on the way from monolatry to Second Temple Judaism's monotheism.
But in general I'm very wary of non-academic books presenting grand theories that cannot be well backed-up by academic sources, even when by an author with academic credentials. Reminds me too much of Guns, Germs, and Steel.
"His" main critique is against evolutionary theology which is common amongst reformers and Christian critics. "God was seen this way. Then it changed and he was seen this way. OT God is angry. NT God is compassionate etc" This is not a new idea and has been held by the Orthodox church since it's inception and has been codified for the last 1200-1300 years. The Orthodox view everything consistently through a Christological lens which is why their view of sotieriology etc is so different than what you will get from Protestants or even Roman Catholics.
Fr. Stephen De Youngs book is just a readily consumable encapsulation of ancient arguments, historical findings (such as the Rosetta stones) with his own analyses and contributions. Would you be better off reading the church fathers and primary sources yourself? Possibly but you'd also need to know ancient Greek and Hebrew.
Christians and academics love to argue and I'm not surprised to see that people are critical of the book. I don't think there is any religious commentary that hasn't received criticism.
At any rate I encourage you to look at Orthodox theology more generally. You will find a logical consistency and depth of analysis that the secular world usually says is lacking in the Christian worldview.
As you said, that does depend entirely on God having those properties, exactly as you define them.
Alternatively, if definitive property is "universal consciousness", then God clearly must exist. Either consciousness is an emergent property of sufficiently complex systems, in which case the entire universe is obviously more complex than the human nervous system and consciousness should certainly emerge within it; or, consciousness is some external field, like gravity or electromagnetism, that complex systems can channel. Either way, the existence of your own consciousness implies a universal one.
I don't think your alternative proposal makes sense, at least not to me. An emergent property being present in one complex system doesn't imply that it must be present in all complex systems.
What does imply it's presence, then? The emergence of comparable effects is implied by isomorphic complexities. If you can't define the foundational structure which implies emergence, you can only fall back on a probabilistic approach.
Unless you can define exactly what structure it is that belies the emergence of consciousness, you must acknowledge that the comparative complexity of a more complex system is undoubtedly probabilistically suggestive of at least comparable, if not far more complex, emergent behavior.
The proposition that consciousness is emergent, but only at a very specific and narrow band of complexity, falls quickly to Occam's razor. It's logically and probabilistically ridiculous.
My point is that not all complex systems are the same. Maybe it depends on your definition of consciousness but from what I know we have only ever observed that in a very specific set of complex systems which is brains and possibly fungi. Two different systems being complex isn't enough in my view to infer that they would have the same properties unless there are other similarities.
It absolutely depends on your definition of consciousness. Every conversation about a concept depends on the definition of that concept. My definition is based upon sensation, processing, and decision-making, in regards to the self and the environment. I'd argue that plants and even cells exhibit simple forms of consciousness. If you take the emergent-property perspective, I'd argue even molecules and individual particles have a broad and abstract consciousness, although certainly several orders of magnitude less sophisticated than yours or mine.
The statement "we have only ever observed that in a very specific set of complex systems which is brains and possibly fungi" tells me less about consciousness than it does about our ability to observe it.