Most atheists are willing to like religious people, no matter the stripe, but that doesnt' work the other way around.
And how well have Catholics and Protestants liked and respected each other. I also a have personal belief many Christians feel threatened by non-believers because we force them to look at their own beliefs and they really don't want to look too deeply into those things they have been taught that make absolutely no sense to someone with a certain level of intelligence and the ability for critical thought. IMO