The premise of the book is that Screwtape is a devil, and uncle to another devil called Wormwood. This uncle Screwtape writes letter after letter to Wormwood, advising nephew how to best pull this new Christian (the "patient") to which he was assigned to recover into "Our Father's House", meaning hell and away from the Enemy (God). Right near the beginning, pg 8-10, is the crux of what pulls most of us away from God - distraction.
The trouble about argument is that it moves the whole struggle onto the Enemy's own ground... By the very act of arguing, you awake the patient's reason...Even if a particular train of thought can be twisted so as to end in our favor, you will find that you have been strengthening in your patient the fatal habit of attending to universal issues and withdrawing his attention from the stream of immediate sense experiences. Your business if to fix his attention on the stream. Teach him to call it "real life" and don't let him ask what he means by "real."Screwtape goes on to give an example of where his "patient" was being persuaded by "The Enemy" and he was about to lose him, but because of his experience, he knew just what to do - he "struck instantly at the part of the man which [he] had best under [his] control, and suggested that it was just about time he [the patient] had some lunch."
...the patient brightened up considerably; and by the time I had added "Much better come back after lunch and go into it with a fresh mind," he was already halfway to the door. Once he was in the street the battle was won. I showed him a newsboy shouting the midday paper, and a No. 73 bus going past, and before he reached the bottom of the steps I had got into him an unalterable conviction that, whatever odd ideas might come into a man's head when he was shut up alone with his books, a healthy dose of "real life" (by which he meant the bus and the newsboy) was enough to show him that all "that sort of thing" just couldn't be true. He knew he'd had a narrow escape, and in later years was fond of talking about "that inarticulate sense for actuality which is our ultimate safeguard against the aberrations of mere logic." He is now safe in Our Father's house.Doesn't that chill you to the bone?