"I am a liar"
People seem to mainly interpret this in two ways: The first is the "woaaahh god lies how cool" way; the empty-headed way that seems to fill the official comments section and doesn't get reflected on beyond people adding various lie-themes to their asinine roleplay.
The other way I see is more common here, and that is taking the lies as something of a cynic meta-commentary on everything on the comic being uncertain and maybe not true, both in-universe and as part of ABADDON's writing.
Both of these perspectives latch unto a very literal and tunnel-vision view of god declaring himself a 'liar'. People assume this means a 'lie' in the sense of saying you have $100 when you just have some pocket lint, or in the sense of shitposting/trolling where you say something false to rile up people or make them do something.
But when you refer to things like the nature of the Art, the creation of the universe, and Yisun's reason for divine suicide, you can pick out the (or a, because it would be hypocritical to say I have the only true meaning of word who's main problem in interpretation is people getting focused on only one interpretation) meaning of "lying" in the divine sense.
Lying is telling a story. God committed suicide to tell the lie (story) of separation from the circular existence as "I" in order to tell more stories (lies). Thus god exists as the ultimate liar because every action of god, and indeed everything that occurs in the universe, is a lie (story and/or narrative) to the undesirable 'truth' of all existence being a singular point.
The creation of the wheel reinforces this, with the method of the gods creating their universes being 'telling a story' that became a universe.
without the context of the story even, you can philosophically argue that a story is just a lie that we accept in a fashion whether we know it is false or not.
KSBD isn't real, but that doesn't stop the narrative from having meaning and existance of it's own.