When the subject is the existence of God, the subject is the existence of God. Right? Right. The subject is NOT the earth, it is NOT the universe, it is NOT beauty, it is NOT the eye
in an of itself.
What would be permissible would be the subject of how exactly God made the earth, the universe, beauty, the eye. But that does not ever happen. Instead you get either overly vague stuff like your "the earth was purposed into existance". Or it gets you notions that if taken at face value are simply silly like this tale about how "the Lord God formed man from the dust of the ground, and breathed into his nostrils the breath of life". Of course, these silly tales are not to be taken at face value, but rather as metaphors for, well, we don't really know.
So, vagueness it is, one way or the other. Something which happens to be called "God" but which is essentially non-descript - ineffable, if you wish - does something in a way which is essentially non-descript - ineffable, if you wish. Absolutely great.
What exactly an 'atheistic' explanation or non-explanation, for, say, "where the earth came from" has got to do with that is utterly beyond me. At worst, you would be left with vagueness along the lines something, somehow, somewhere. *shrugs*
The fun part is of course that ultimately you can't distinguish one vague "something, somehow", from another vague "something, somehow". To do that you would need to dispel the vagueness first. But that does not happen, ever, with "God". You get some sort of illusion of explaining stuff, but you don't actually explain stuff.
If you (want to) dismiss an explanation, you don't have to provide an explanation. Mind, you don't have to, but you could. For example, you could dismiss option A in favor of option B. But as I said, you don't have to; you also could simply dismiss option A because it is rubbish in an of itself. By and large this is position of an atheist. A negative position.
If however you (want to) provide an explanation, then I am afraid that you would also have to do all the necessary work that that entails. By and large, this is the position that a theist who tries to argue "God" as an explanation finds themself in.
Reality is completely different of course, and you'll find that the people who should be making a positive case for something, content themselves to negative argumentation, while trying to shirk all the work of providing positive explanation to those who merely hold a negative position. Totally Ga-Ga.
(For me, the issue is very simple however. If theistic 'explanations' for the complexity of the eye, the earth, beauty morality, the price of rice in China amount to no more than ineffable somethings doing ineffable somehows, then I will draw the consequences from that. No wait, I
did already draw the consequences from that.)