And what specific "beliefs" would they be?
That's like saying people with mustaches shouldn't enforce their evil beliefs onto others (Hitler, Stalin, etc). A mustache isn't inherently linked with any particular beliefs, it is a physical trait.
Similarly, atheism is just a lack of belief in supernatural deities. It is not inherently linked to any other ideologies.
However, Christianity/Islam relies upon the Bible/Quran and therefore such actions from these religions can be inextricable linked to their respective religious texts.
Lol, asserting that there is no God, requires faith in unto itself as there is not proof that God doesn't exist.
In fact, it requires faith to even believe in what science can demonstrate. One must first have faith in the scientific method, the scientists themselves, and subsequently, faith in the universe; that everything is in fact acutually explainable through something as mundane and crude as science or mathematics.
The religion of athiesm proclaims the path of light to the individual, through the study of the holy scripture "The God Delusion" and worship to it's saviour Richard Dawikns himself.
Ok on a serious note now.... Christianity is just the belief in a loving and sympathetic God, it is not tied to hate crime or religiously inspired murder or the like. You can claim that the religion fosters negative attitudes to homosexuality, which it does, it is described as a sin, a moral wrong. However the Bible also teaches us to love our neighbour, to be charitable and not to judge people "let he who has not sinned cast the first stone".
And the Bible is not Christianity in a book. There are apsects of the faith outside of the Bible. It is possible to be Christian without having read all of (or even any of for that matter) the Bible. The Bible is an important reference tool for the faithful, but not simply a list of rules (although it does present some) and should not be seen as such.