wolfrom said Arrington right and McClure honestly believe.
Believe is very different to wrong. If Arrington is right, McClure is wrong in his belief. He can still honestly believe it though.
One, or all, of Christians, Muslims and Atheists are wrong in their belief, but they can all honestly believe.
I'm not being pedantic here, if you read wolfrom's statement with the correct meanings you'll see how wrong your comment is, even if you honestly believed it.