As Screwtape passes on his wisdom in how to keep people out of the Enemy’s camp (and thus away from Christianity), we find that one of the main tactics of the demon is ignorance.
As always, the first step is to keep knowledge out of his mind.
For example, the Enemy (God) wants us to be concerned with eternity (thinking about Himself) and the Present, Wormwood is reminded that his chief task is keeping the patient distracted and focused elsewhere.
Our business is to get them away from the eternal, and from the Present. … [The Past] is of limited value, for they have some real knowledge of the past… It is far better to make them live in the Future. … [as] nearly all vices are rooted in the future.
