My Dearest Wormwood,
The Enemy's followers are always coming up with new ways to try to spread their message and take people away from our side. With each new advance in human media technology, while some of them will balk at its use, claiming it comes from the depths of our domain, others will find a use for it in their efforts to enlist more people in their cause.
To defeat the Christians in their attempt to use media and technology to recruit more people for the Enemy's side, a direct frontal assault is not as effective as it used to be. While some of our captives will still pay heed to our denials of any validity to the Enemy's message, it is becoming more and more difficult to keep humans thinking on a purely naturalistic level. Our propaganda campaign with the "New Atheism" of the past generation, rather than convincing more people that the only thing that mattered was physical life, backfired, ultimately having the opposite effect. While people may not have converted to the other side, many individuals did end up thinking more about eternal matters, and some of them defected from our ranks. It's better for us if humans stay completely in the dark about the eternal component of their existence.