Evil god is an entity of which none worse can be conceived. If you could imagine an entity worse than evil god, then that being would be evil god. By definition, a maximally evil entity would be maximally hateful, maximally cruel, and maximally selfish. (1)
Evil isn’t a privation of good; rather, evil is identical to existence itself. Evil god is existence itself, and evil god’s existence is identical to his essence. Evil god isn’t just another god or entity. In other words, it is impossible for evil god not to exist; evil god exists necessarily. Necessary existence is an attribute of evil god.
As a professional Philosopher, I’m convinced that evil god makes sense of a wide variety of data in the world, including philosophical, scientific, moral, and historical considerations.
The Cumulative Argument
A cumulative case argument can be made for the existence of an evil god.
A) The first argument is an ontological argument for an evil god:
1. It is possible that a maximally evil being exists (i.e. MEB)
2. If it is possible that a MEB exists, then a MEB exists in some possible world
3. If a MEB exists in some possible world, then a MEB exists in every possible world
4. If a MEB exists in every possible world, then a MEB exists in the actual world
5. If, if a MEB exists in the actual world, then a MEB exists
6. Therefore, a MEB exists
Now it might suprise you that steps 2-5 are relatively uncontroversial. The only question is whether premise 1 is true. I’ll ask you-do you think that it’s at least possible that a MEB exists? There doesn’t seem to be an explicit contradiction with the concept. Therefore, it is possible that a MEB exists. Thus, it follows logically and inescapably that evil god exists.
B) Now for my second argument, the dystelelogical argument.
The universe and planet earth are very hostile to life. Life can only exist in a small portion of the universe. The universe is hostile because evil god adores hostility. The universe is perfectly fine-tuned for hostility. If the constants were tweaked even a little bit, there wouldn’t even be stars.
Formally put:
1. The fine-tuning of the universe to allow for hostility to life is either due to necessity, chance, or design
2. It is not due to chance or necessity.
3. Therefore, it due to design.
C) Now for my third argument, the moral argument:
1. If evil god does not exist, then evil does not exist
2. Evil exists
3. Therefore, evil god exists
OBJECTION! : Is something evil because evil god commands it? Or is something evil independently of evil god? If the former, then evil is subject to the arbitrary whims of an evil god. But if the latter, then we don’t need an evil god to ground evil.
I answer that evil god is the paradigm of evil. Evil god is evil itself: the ground of all evil (i.e. evil god is The Evil). Evil exists, and deep down we all know it. There’s no more reason to deny that evil exists than to deny the reality of an external world. But if you agree with me that evil exits, then I’ll think you will agree with me that evil god exists.
D) My last argument is not really an argument at all. Rather, it’s the claim that evil god can be personally known and experienced wholly apart from argument or evidence. This is what philosophers call a ‘properly basic belief’. When one sees a baby tortured or an ugly animal, one immediately comes to believe in an evil god. Draw away from evil god, and he will draw near to annoy you. Thank you.
Notes
(1) This post is satire.
Philosophy of Religion blog 
This post is satire
Yes, but this is the very best satire. The argument is surprising robust, and certainly more historically accurate than any ‘good’ god hypothesis. The Creator, though, doesn’t necessarily have to be evil (which produces a number of historical/teleological problems), rather simply curious. My central thesis builds from this:
Have you heard of Stephen Law’s “Evil God” challenge? I think Feser took a look at it some time ago.
Yup. Also, I did read Feser’s responses.
I don’t know about satire so much, but you do poke holes in the various arguments for the existence of god (of which I have collected dozens), the biggest of which is that the arguments cannot specify which god. They apply equally to the Flying Spaghetti Monster, Allah, and Zeus. Consequently these arguments are simply for the possibility that their god exists.
These arguments are so lame that only a believer would accept them uncritically. For example in the Ontological Argument we have “It is possible that a maximally evil being (aka whatever) exists.” The premise is clearly flawed. Jesus doesn’t qualify, nor does any other god who has a mother (who had a mother herself, and she had a mother…. And to accept this is to accept a failure of imagination. If you were to characterize any such being and then gave that characterization to marvel Comics, they could whip up an imagined being that was more powerful still and do this ad nauseum. I think they would be better off following Clarke’s First Law: Any sufficiently advanced technology is indistinguishable from magic. All they need is a being that powerful to be their god, why go overboard making false claims that just cannot be true when there are more acceptable claims that get you home.
I’m convinced that apologists don’t understand what philosophy can do. I get the impression that they think we can get meaningful answers about reality just by sitting in a chair.
Evil god is an Oxymoron! God cannot be evil and still God. You argument begs the question. You presuppose that God is evil which is the same as saying the God of the Christians who is all-good does not exist. Your conclusion is already in your premise!
You’re attacking a strawman. I never said “God” was evil. I said ‘god’. By the way, who said that Yahweh is God? In other words, who said that Yahweh is all-good? Now who’s begging the question? lol.
You’re also equivocating on the word “God” to not only include generic omni-theism but Christian theism as well; those aren’t identical.