Do religious people believe that willful ignorance pardons deliberate deception?

Yes, I think they definitely do. Religion is such a well-established thing now that it's going to take a while for it to go away. Religion is a very pervasive and persistent virus of the mind. Even people who absolutely do realize it's baloney stick with it because they don't know what else to do, or, they have a strong belief in belief itself. They're afraid if they let go of their belief, and no longer profess it to others, they fear their lives will change in scary ways they can't control. They really think that people believing, or professing to believe, is the glue that keeps their world together. They don't care if people actually believe ridiculous religious claims. Most don't. But they believe in belief. Without it, they fear catastrophic collapse of their society. So they perpetuate the myth, they keep pumping life into the poisonous religion meme that warps people's minds from childhood. They seem to find comfort in clinging to the group, playing along, trying to have "faith" despite mive cognitive dissonance. It may just be a dependence on the familiar, and on effective brainwashing that convinces them that not believing is worse than believing.