From the perspective of psychology, telling someone "You don't want to know" is an example of invalidation. It's saying "I don't really care what you think or feel, Q."
It may be true that Q "doesn't want to know", and he has been told such things over and over again - yet nothing has changed.
Invalidating people generally does not help them toward an insight.
I would like to see that you come up with a novel, more compassionate, more productive method for talking to atheists.
They are people too, you know.
I think that its important for him to sincerely ask himself that question, "do I really want to know?" and examine the implications. Not to answer the question on here, but to himself. I think its the most important question anyone could ever ask themselves.