What's the difference between atheism and theism?

Atheism

Definition:

(n.) The disbelief or denial of the existence of a God, or supreme intelligent Being.
(n.) Godlessness.

Example Sentences:

(1) One of the problems I have with the New Atheism is that it fixates on ethics, ignoring aesthetics at its peril.
(2) And over the years, he has been unapologetically opinionated, not just on behalf of his fellow scientists, and on behalf of Britain’s disabled, but on wider matters: he joined an academic boycott in protest against Israeli treatment of Palestinians; he backed a recent $100m project to accelerate a tiny spacecraft to a fifth of the speed of light and send it to the nearest star system; he has spoken in favour of assisted suicide for the terminally ill; he has spoken up for atheism; he has made ominous pronouncements about artificial intelligence research; and he has even invited the fans of One Direction to imagine an alternative universe in which Zayn Malik was still with the band.
(3) I think it's in Kansas, you'll have to fact check that, that they're not teaching evolution theory anymore, and apparently there was an online poll of English teachers, British teachers and it was something like 60% thought it should be taught alongside creationism, which for me is really shocking, but... Like I say, I don't think it is a film about atheism, but for me, as an atheist, to have a viable alternative is incredibly important.
(4) Stressing the jolly side of atheism not only glosses over its harsher truths, it also disguises its unique selling point.
(5) How does he feel that, in the US, this summer’s bestselling author on race hails not from the black Christian activist tradition, but from a place of secular atheism that is not especially optimistic?
(6) • This article was amended on 27 September 2013 to clarify that pupils in multi-denominational schools will learn about atheism as part of the wider curriculum covering ethics, beliefs and religion.
(7) The religionists haven't helped themselves, though; surely the new atheism is in part a reaction to the rise of, say, Islamic extremism?
(8) But the religious extremists explained it as destructive ideas against God.” The case went to trial in February 2014 when the complainant and two members of the religious police told the court that Fayadh had publicly blasphemed, promoted atheism to young people and conducted illicit relationships with women and stored some of their photographs on his mobile phone.
(9) Although atheism can be just as oppressive as any other belief system if it becomes the official religion of a repressive state, as the Soviet Union amply demonstrated, I've never heard of any member of Egypt's marginalised, unrecognised and forgotten atheist minority ever calling for a "jihad" or "crusade" against believers.
(10) But during the decades of the Franco dictatorship, a counter-version of history was prosecuted with ferocious energy, one in which Nationalist soldiers stepped in to save old Catholic Spain from the alien, hostile forces of atheism and communism.
(11) That is why, even though many Poles feel entitled to accuse the EU of encouraging atheism, individualism and immorality, an amazing 75% of them want to stay in the EU.
(12) It may be helpful to the church that his shift of position makes it harder to portray the discussion as one between rigid doctrine and compassionate atheism.
(13) Sadiq Khan urges Corbyn to back Gatwick expansion Read more The adult Shelley’s atheism later outraged the local population.
(14) He describes himself in his most recent work Consilience as having been "laid backward under the water on the arm of a sturdy pastor" and while his atheism was complete before he went to university, he understands the need of what he calls the transcendental experience at the heart of human nature.
(15) Jane Donnelly, a member of Atheist Ireland and a parent of two children in an Irish secondary school, welcomed the creation of an atheism alternative for Irish pupils.
(16) The regime is also working on plans to “eradicate” atheism.
(17) The last time I put my own atheism through the spin cycle rather than simply wiping it clean was when I wanted to make a ceremony after the birth of my third child.
(18) They accused me [of] atheism and spreading some destructive thoughts into society,” said Fayadh.
(19) She cited major upcoming BBC4 documentary series by polymath Jonathan Miller, on atheism, and another about the key role light plays in the visual arts and media.
(20) He touches on biogenics by way of the inevitable Richard Dawkins – "This kind of extreme atheism misses the point of religion entirely" – and illustrates how science has lost its monopoly on truth.