“Atheism is the state of disbelief or non-belief  in the existence of a deity or deities.  It is commonly defined as the positive denial of theism (ie. the assertion that deities do not exist),  or the deliberate rejection of theism (i.e., the refusal to believe in the existence of deities).”
“Theism is the belief in the existence of one or more divinities or deities.”
I believe that an agreement can be reached between theists and atheists that will end their age-old conflict about the creation of everything, and allow them to proceed to another discussion or controversy.
All that is required is sanity. I believe that there can be sane theists and sane atheists; and there can be delusional people who call themselves either theists or atheists. I assume, for purposes of sane discussion, that there are no delusional people, either theists or atheists, here right now.
A workable (not absolute) criterion and procedure for differentiating sanity from insanity can be the distinguishing between reality and illusion.
The sane can accept that everything is. Another way of stating this is that the sane can accept that what is, is.
The sane also recognize that what does not exist is not a part of what does exist. This is a clear arithmetic statement, perhaps as basic as is humanly attainable, on which sane theists and sane atheists can agree.
The delusional will insist that something that does not exist is, or could be part of what exists. The delusional will necessarily have to redefine existence as nonexistence; or reality as illusion. But by definition, and pursuant to the rules sane people live by, these delusional redefinitions cannot be true.
If there does not exist a purple elephant, not even the proverbial one, then a purple elephant is not part of everything. If a purple elephant is brought into existence, then it will be part of everything.
We, quite obviously, do not know what is included in everything. We do not know, and perhaps cannot know, if even herds of purple elephants are included in everything that exists. But we can know that what exists exists, and that it is everything that exists, or simply, everything.
Mathematics is (my dictionary says) a science that deals with the relationship and symbolism of numbers and magnitudes and that includes quantitative operations and the solution of quantitative problems.
Math is and works the same for theists and atheists. These two groups of people can both use the same sets of numbers and magnitudes and both do the same mathematical operations with the same results. Theists and atheists may at times apply math to different problems, but the math can be the same.
What constitutes everything is arrived at by the simplest of mathematical operations, addition. Everything consists of its bits or components added up. It might be that multiplication or quanta, for example, are real, so they can be added in.
It is true that an imaginary everything can be calculated in exactly the same way, by addition of its parts, and, being imaginary, can be of any imaginary magnitude. But it is not necessary to consider imaginary everythings, or imaginary anythings, in order to consider the arithmetical calculation of the real everything.
It is also not necessary in considering the calculation of the total of everything to determine or answer the question of whether the physical world is an illusion, or whether a part or aspect of the world is illusion. Whatever is illusory simply is not part of what is real, and not part of what adds up to everything. This is true without knowing or having to know what if anything is illusory and what if anything is real.
So sane theists and sane atheists can agree that everything exists; or, again, said another way, that what exists constitutes everything [that exists].
Sane theists and sane atheists can also agree that everything that exists came from something or somewhere. Without considering the nature or qualities of what or where everything comes from, that is, the nature or qualities of what caused everything, it is possible to accept and know that it was caused by something. If everything has always been here, then it is causing itself and always caused itself. But again, putting aside any discussion of the cause’s nature, it can be seen that whatever is real has a cause.
The nature of what caused everything that exists could be a big bang, it could be a spark in mud, it could be an error, it could be a non-error, it could be conscious, it could be unconscious, it could be a one-shot deal, it could be a continuing process, it could be everything itself. It is not necessary to know what caused everything to know that everything was caused.
It could be that today’s oak tree is caused by an acorn of two hundred years ago, or by that acorn’s cause, which could have been another tree and another acorn two hundred years earlier; or by the acorn plus all the sun, soil and water over the hundreds or thousands or millions or billions of years. It is not necessary to know what caused the oak tree to know that it was caused; if the oak tree exists.
It is not necessary to know if identical or different factors comprise the cause or causes that brought into effect two different parts of everything to know that the two parts were caused. The oak tree has, for example, its seed, sun, soil and water, if those things comprise its cause; and the clam has its parents, its seed, its sun, its soil and its water too that cause it to be part of everything.
It is not necessary to know if the cause for anything that exists knew what it was doing in causing that thing in order to know that there was a cause. Even if whatever was caused was caused by quote accident it still had a cause.
Just as everything that exists at this moment can be determined by the simple arithmetic operation of addition of its parts, so too can everything that caused everything that exists be determined by adding up that cause’s parts.
Just as it is not necessary to know what all the parts of everything are, and what the nature of all of the parts is, to be able to know that they add up to everything, it is not necessary to know what all the parts are of what caused everything, and what the nature of all the parts that caused everything is, to be able to know that they add up to everything’s cause.
That sum or totality of whatever, in the beginning or at any time, caused that which exists is properly called “God.” The theists have almost owned the word, and the atheists, to my knowledge, have oddly objected to using the word, but have never really had another word for it. Fitting “that sum of whatever, in the beginning or at any time, caused what exists” into all the places a person could say “God” is so cumbersome and goofy that the atheists perhaps avoid even getting near those places at all.
God, as the cause or Creator of all that exists, without considering God’s nature or qualities, is what sane theists and sane atheists can agree upon. They can talk together about oak trees coming from acorns, thoughts being created by minds, or man causing pollution, overpopulation or his own destruction. And now sane theists and atheists can talk about God, those causes added together that resulted in whatever is real.
Whether that cause or Creator created everything in Love, or is a God of Love, or an all-knowing God, or a just God, or is in fact Everything Itself Anyway, does not have to be considered to know that the sum of all causes caused all that is.
God could be a force, an “accident,” a wave, a particle, a static, an evolution or a Big Bang, but these natures or qualities of God do not have to be considered to know that God, the sum of all causes, caused all that is.
It is true that knowing that God caused or created everything might very well cause a search for God’s nature and qualities, and even God’s intention, reason and wisdom. Very possibly, some people will be led to a belief that God is omniscient, omnipresent or all-loving; and some people may be led to a belief that God is capricious, mechanistic or even hateful. Some people may be led to the belief that God caused everything and then left the building. These beliefs might influence people’s lives, but it is not necessary to know if any of these beliefs about God’s nature or actions are right or wrong to know that God caused or created everything.
This proof is sound biblically, conforming to the words and thought contained in John 1:3 (KJV) “All things were made by Him; and without Him was not any thing made that was made.”
A usual response from someone who takes offense at this simple proof is to try to project a straw believer’s qualities for God onto the basic identity of God, which is given here deliberately without qualities. It will be argued that it is improper to use the word “God” without considering God’s nature and qualities beyond God’s being “the sum of all causes for everything.”
Either there is a cause for what exists or there is not. If there is a single cause, the theist says, the name for it is “God.” If causation has component parts over time that added together form the sum of all causes, the theist says that the name for that sum is “God.” No nature or quality of any part of that cause or sum of those causes is considered in calling it “God.”
In order to prove that the cause for everything could not be God; that is, that the cause for everything could not be the cause for everything, a person must start by proving that there could be no cause for anything. Since we are so overwhelmingly surrounded by everything that exists, and form ourselves a part of what exists, such a “proof” can only be “accomplished” by resorting to delusion or insanity, and pronouncing everything to be nothing, reality to be illusion.
There is no need whatsoever to sacrifice our God-given, or God-caused, minds and to opt for delusion. The simplest conclusion happens to be the sane one. Everything exists. God did it.