You live in that world. 2+2 does equal 4. The atheist says 2+2=9 because Athiesm is a religion and to be a good Atheist you must reject the Bible, the Torah/Talmud, the Koran, and any other references to deity. Therefore, any number that the others believe is correct - even if it is 4 - will be rejected out of principle.
Someone (Atheist, Christian, Jewish, Muslim, HIndu, Buddhist, ... you pick it) is going to get mad and condemn you no matter what you believe. If you are waiting for that world of no condemning to come about, then you might as well go ahead and check out of this one.[/QUOT
If I say I am an Atheist it means I don't have a religion. I also, don't believe in supreme being,either. In my world, no god or religion is 4.