Error 404: The page you are looking for can not be found. You may have mistyped the address or it may have moved.
If this happened on an atheist web site there might be an opportunity for a little fun. What might we like the error message to say?
Error 666: The deity you are seeking can not be found. You may have prayed to the wrong entity or failed to find the true way.
Perhaps you have a better suggestion and might be tempted to leave it in the comments.