When a word or phrase ordinarily and primarily used for one thing is applied to another the result is a metaphor. Metaphors rely on utilizing one or more words whose actual definition renders the sentence nonsensical or false. The sentence must be reinterpreted non-literally by substituting a context sensitive inferred meaning for the actual meaning of one or more of the words to extract it's intended meaning. For example "all the world's a stage", "he drowned in a sea of grief", "she is fishing in troubled waters", etc. Metaphors implicitly compare a situation to something else, but the situation is not actually that particular other thing and that other thing may itself be fictional.
A factual assertion that an entity of type X does not exist is not contradicted or challenged by citing the use of the noun for X as a metaphor. It is silly to argue that a sea of grief exists because at some point in our lives many people experience the sentiment of being drowned in a sea of grief. This is a variety of category error. Metaphors interpreted literally are false and therefore cannot be rationally cited as evidence to demonstrate that the thing referenced by the metaphor actually exists.
Yet so-called "sophisticated theology" relies on such misuse of metaphor to argue for the existence of a god. An open reliance on metaphorical interpretations gives liberal theology in particular more flexibility than the more literalist conservative theology. Liberal theology often puts this flexibility to good use in selectively shedding itself of the most blatantly untenable content of its holy books by dismissing it as metaphor. Good metaphors are meaningful, so by converting falsehoods into metaphors the falsehoods can be converted to potentially meaningful fiction. But a reliance on converting falsehoods to meaningful fictions can only go so far. Religion needs something more than meaningful fiction alone to justify the clerical salaries. Religion needs factual content. Both liberal and conservative theologians will cite metaphors as evidence for factual claims. In particular, they rely on metaphors as substitutes for evidence of the existence of divinity.
The desire for a god to exist is so strong that many people consider it a serious character flaw to not believe in a god. Famous people, particularly if they hold positions of responsibility, will often be challenged to publicly aver a belief in god. If that famous person wants to avoid becoming a target of popular disdain and derision then that person is obliged to respond affirmatively. So the best that they can often do under the circumstance is give a metaphorical response to try to have it both ways. The problem here is that by doing that we play into the hands of sophisticated theologians who take that gift ball and run with it, claiming that the celebrity has publicly endorsed belief in their god. I know from personal experience that many people cite such publicly stated metaphors from people such as Einstein and Hawking as support for their belief that theism is more reasonable than atheism. This further isolates us atheists.
When someone says god is the "ultimate ground of being", we can respond by paraphrasing Abraham Lincoln, who once said "How many legs does a dog have if you call the tail a leg? Four. Calling a tail a leg doesn't make it a leg". How many gods exist if you call the ultimate grounds of being a god? Zero. Calling the ultimate grounds of being a god doesn't make it a god. Richard Dawkins is correct when he asks "There is no evidence for it, but you can't prove that there aren't any, so shouldn't we be agnostic with respect to fairies?” Supernatural types of willful agents that reside outside the laws of physics are all in the same boat, there is insufficient reason to give gods more slack than any other such imaginary, supernatural entities. Accommodating popular intolerance is not a good reason.
It is better to not hide behind the metaphors. If you believe that there are no immaterial willful agents, no immaterial minds, no creator and chief managing administrator of the universe, then come out of the closet. Say so publicly and unambiguously. Call yourself an atheist.