We? Call yourself an Atheist? Atheists claim the universe was created from nothing by chance with no purpose. So much so they come out with the nonsense of multi-universe hypothesis which has no evidence in an attempt to counter fine tuning of the universe. You are no different to Theists, you have hope, you have faith, that the universe was created from nothing and all can be explained in terms of chance, matter, and time.
If you claim you do not know how the universe was created, that makes you an Agnostic.
My suggestion to you is instead of asking theists for evidence of God, why don't you do a little reading on what Atheism actually believe with respect to science, and find out what you really believe in.
God cannot be observed in any physical manifestation, very much like a force of the universe. We cannot observe forces, but we can observe the effect of forces, in the same way theists will argue that they can obverse the effect of God.
When you come off the bandwagon that science disproves religion, you will realise that both religion and science compliment each other - but first get a grasp on what you actually believe in before you demand evidence from others.
You have lot of misconceptions about Atheists, they are not very organized to begin with. Let me have a shot the thinking behind Atheists...
There are two Propositions or Claim possible about God:
Prop 1: God Exists, with Characteristics defined by Theist:
This proposition that not only God Exists, but with specifics details, presented in most if not all religions. Throughout Human history 3000+ Gods of various kind in all human cultures have been presented, with little to no evidence of their existence.
Atheists specifically deny all of these Gods, that's why 'A' in the 'Theist' comes from. Primarily, since no evidence has been presented of existence of any of those Gods. Many if not most of the characteristic of Gods are Scientific in nature, hence requires Scientific investigation rather than belief. The primary reason they are scientific in nature, at the end they interact with physical world. We don't see signs of God interfering with physical world, as claimed by theist. Nor they are able to present any evidence of how God interact with physical world, how he created the world? Or How he was created in the first place?
Prop 2: No God could ever exist.
This proposition is not something Atheists believes in, for this to be true, we have to evaluate all the possibilities and then nullify this hypothesis. In Logic or philosophy this is called 'null hypothesis' which cannot be falsify. Since we cannot first of know what possibilities exists, so evaluating them is a step further.
Atheists don't focus on this part, that will be waste of time and stupid to begin with
Origin of matter/universe/life
Origin of things(matter/life/universe etc) is still an unknown entity in the realm of Science. There is no reason to assume that it will be like that for ever. Infact lot of phenomena considered impossible to understand, are no more the case. Religion has failed and way off the mark for most of them. Theist are jumping on origin now, since this is the only place left for them to jump on, this is where GOD of GAPS comes in.
Religion Fails at explaining Operation of Cosmos:
Religion has not only talked vaguely about Origin, but a lot of focus on Operation of the Cosmos. Earth Quakes, floods, Hurricanes, epidemic diseases and many natural disasters are considered to be work of God, when he is not happy with certain group of people or community etc. This is how many stories goes in Ibharimic religion, many of them were copy/pasted from local legends and culture of that time

But reality is all these natural disaster has nothing to do with God, but more to do with Geology, Climate of planet and star system you are living in. All of them can be explain by Science. This also shows, all these religions were Scams to control poor people by fear.
There are no angles who control wind or water, as deemed by many religious folk tails. Cosmos works on laws of nature, not angles and demons. There are no angles or demons interacting with Cosmos, nobody has presented any evidence of that. Again that was fear tactics, taking advantage of lack of knowledge of masses.
Same goes for Adam/Eve story, which is complete garbage, there never was first Human or first of any species. Evolution does not work that way, again religion is completely false on that...Religion also cannot explain why God took 13.7B years to create Human? if that was purpose of universe, it should have been done in the beginning... Similarly, Earth is no Central focus on universe as presented by religion...List can go on and on...
Scale, depth and breath of only our Universe is greatly underestimated by all religions, with the help of Science we are beginning to know about it. Same goes for micro biology. Plagues and other micro organism diseases are not curse of God, but are now understood thanks to advancement of Science and Biology. Prophet of Islam himself had suffer infant child deaths, because it has nothing to do with God, more to do with advancement of modern medicine to control infant death rate, which cause exponential growth of human population. Brith and Death are not controlled by God, another fearful idea propagated by religion and falsify by Science. Most of the operational aspects of religion are falsified by Science. They never presented proof of their universe operation model either, by Science proof, they are not only wrong, but completely off track, their motives have been to control people by fear, its all nothing by SCAM.
Religion will jump on anything not know at the time and bring Spiritualism and other garbage in it. Now their only play ground is Origin, its not like they have contributed anything to solve that problem, but rather leading people to more ignorance. They have zero track record of demystifying anything in past. Spiritualism is garbage, we have not discovered anything using that tool. Most of religion is a political tool, politics of fear is what they are good at. They have no substance to offer, want to control people by fear. They want masses not to focus on reason and evidence base knowledge, which has been most successful tool we have ever created in human history. We have been most successful when we focus on evidence based reason!!