A quick Google search turned up more than 2 million hits for the phrase "war on Christianity"
Which is what I did also, and what we encouraged The Big Dog to do in order to dispel his doubt that the phrase was indeed used "in the wild." Asking at length that his opponents explicitly provide examples, as a substitute for such self-service information gathering, is less reasonable, in my opinion...
Sorry, I have to disagree. In skepticism the burden to provide evidence for a claim should be on those making the claim, not on those challenging it.
If a claim is true, as this one is, it's generally not difficult for those of us who believe it's true to find good evidence and display it. If a claim is false it is difficult to find good evidence -- which is why supporters of false claims often play games in which they find excuses not to provide evidence and try to put the burden on those challenging the claim. One of those excuses is Oh, it's easy to find the evidence, it's all over the place, just use Google, I'm not going to do your homework for you... That's one reason it's important that we not legitimize that excuse by using it ourselves.
The fact we were able to turn up 2 million hits is an encouraging sign when one is searching for evidence to support our belief that there are many people who have claimed there is a war on Christianity, but it does not actually show it. That's why it's important to actually check some of the hits, see if they actually support the claim, and if so present the examples, rather than just saying that a search will turn up lots of Google hits.
One can see this with a lot of right-wing echo chamber claims about what liberals supposedly say or believe. A Google search will turn up a very large number of hits -- but the overwhelming majority often turn out to be to right-wing echo chamber sites repeating the claim that liberals believe something rather than to instances where liberals actually said it.
That's why it's important to verify one's evidence for oneself before posting it, and to describe accurately what is to be found at the links and how it supports one's claim, rather than just posting links. That helps those we are discussing a matter with see more easily when valid evidence actually has been provided to support a claim and see more easily when valid evidence actually has not been provided.
As skeptics, what we should want are methods which make it easier for people to see that a claim is true (if it is true) and easier to see if a claim is false (if it is false). A good method for doing that is for people who make a claim to present the evidence in support of that claim in clear plain language. The method you're proposing -- that the burden is on those challenging a claim to find the evidence supporting the claim -- instead makes life easier for people promoting false claims.
