Ofcourse, it wouldn't make a lot of sense to group and act upon a lack of belief. Atheists just often share similar world views and are passionate about similar issues. I was only using OP's words.
Uh, OK. Welcome to England, where all but one of Britain’s six prime ministers in the past four decades have been practicing Christians. Their decisions are influenced by their beliefs just like everyone else. For example, in Theresa May's words, Christianity gives her "a moral backing to what I...
We take action because religious individuals hold power at every level of government and create/legislate laws, and make important decisions that are influenced by their religious beliefs. Many of these are decisions made solely due to religious doctrine.