In these two verse we are told that "sin in crouching at the door" and "the Devil prowls like a roaring lion":
Genesis 4:7: "If you do well, will not your countenance be lifted up? And if you do not do well, sin is crouching at the door; and its desire is for you, but you must master it." (emphasis added).
1 Peter 5:8-9: "Be of sober spirit, be on the alert. Your adversary, the devil, prowls around like a roaring lion, seeking someone to devour. But resist him, firm in your faith, knowing that the same experiences of suffering are being accomplished by your brethren who are in the world." (emphasis added).
Just how is the Accuser "crouching at our door" or "prowling around us" if we never witness any audible or visual sense of his presence? How does his influence affect us - unless he is somehow able to manipulate certain thoughts? Or, to put that another way, how do the subtle temptations we face often appear to align themselves so precisely with our most private, inner reflections?