Why do Christians think all Atheists are Communist?

[Do] all Christians think all Atheists are communist? [Do] all Atheists think all Christians are not worshipping the one true God? The situation is this, it's a matter of choice and if you make the wrong choice you [ could ] end up in a not to pleasant place.[ Some ] Christians and [ some ] Atheists could feel that way I suppose but lets not generalize to the point of being ridiculous.