Atheism is not a claim it is the rejection of a claim. The proof is on you not me.
Cosmology and evolutionary biology provide enough evidence to convince a rational person that the universe and life on Earth came about naturally, i.e., without the involvement of any supernatural beings.
I am an Atheist and also an Anti-Theist. These two different things do not go hand in hand, and are quite possibly unrelated to one another. To simplify, not all Atheists are Anti-Theists, not all Anti-Theists are Atheists. I will note that my philosophies are more defined by what I am not than what I am.
A (meaning without) theist (meaning belief in god). Therefore, a literal translation of Atheist = without belief in god. Anti-Theist, meaning against belief in god. While a great deal of Atheists are Anti-Theists, not all of them are. Anti-Theism meaning the belief that religion and religious belief is harmful to society and culture. Meaning that I am personally in direct opposition to theism. Many Atheists that simply do not have the concept of a god belief are not Anti-Theists, because they hold the position that as long as religion is not interfering with governing bodies, laws or trying to force people into its indoctrination, that there is no harm in religion. This is a point I wholeheartedly disagree with.
But, I do find it interesting that all three of the words that hold my strongest views in life, imply the absence of or the opposition to a belief. It occurred to me, that almost all of my ethics and worldviews are formed by all of the things in the world that I am ardently opposed to. I am opposed to religion because of the poisonous doctrines and ignorant systems of belief that it spreads to people, I am opposed to people continuing the existence of life, because I am opposed to pain and suffering. I am opposed to belief in god, because of the harm that such delusion can bring . Because science can explain just about everything but not quite, it's wrong to say therefore we don't need [gods]. We don't need the Flying Spaghetti Monster, unicorns, Thor, Wotan, Jupiter, or fairies at the bottom of the garden. There's an infinite number of things that some people at one time or another have believed in, and an infinite number of things that nobody has believed in. If there's not the slightest reason to believe in any of those things, why bother? The onus is on somebody who says, I want to believe in [Abraham's god], Flying Spaghetti Monster, fairies, or whatever it is. It is not up to us to disprove it. Anti-theism is active and vocal opposition to belief in gods of any sort and to institutions built around belief in a deity. Anti-theists are not passive atheists; they delight in atheism and delight in exposing the errors, absurdities, and pretensions of theists. Anti-theists consider all gods to be false gods and any benefits from belief in gods to be far outweighed by the harm done by such beliefs to the individual and to society. Anti-theists don't deny that there may be some benefits to some people some of the time due to their delusional belief in a deity or two, but they adamantly deny that faith in religious books or ideas is a good thing. Anti-theists are usually referred to these days as the new atheists. These anti-theists consider it a moral duty to oppose religion and theism, and to advocate science and reason. Such opposition is for the good of the individual and for the good of society.