No you should believe in whatever you believe even if its nothing .Our society surely reflects how moral we become . Also don't Christians pay taxes ? Why should they be taken down ? Who does it harm ? Its all political ! Do you have any proof there isnt a God ? has It been debunked ? I missed that thread ? Is there not enough data ?
Favoring one religion at the expense of other is un-American. If Christians want to spend their own money to erect a cross on private land then they are free to do so. It's not as if there are no crosses in America - it's just that using public land for one is favoring one particular religion.
You can't prove there is no god. But there's no evidence that there is a god, so why believe in one?