Why do atheists say "Oh God!", "Jesus!", "My lord!" etc?

because atheists are idiots and most of them are just too lazy to believe in their own creator who designed them in their own image. and its just become casual language. The bible says that we shouldn't take the name of the lord in vain, and so christians saying this kind is wrong, and the atheists are sinning by saying this every time, and they will pay the consequence in hell.