My wristwatch has a secret.

The face of my watch has a display that shows the day of the week and the date — a handy feature for Mr. Absent-Minded here. In the early morning hours, beginning at about 1 a.m., the dial transitions from one day of the week to the next (i.e., from “SUN” to “MON”). But here’s the secret: midway through the change, there is an abbreviation in Spanish that has to scroll past before the next day appears in English. This action takes place in the middle of the night, so you might never see it unless you keep odd hours — which I often do.

Now you’re thinking, “That’s not much of a secret.” Perhaps not, but it was a curiosity to me the first time I saw it occur, because it took me a second to figure out what day of the week “DOM” was. The watchmakers count on the fact that few people ever look at their wristwatch at three in the morning, so they’ll never notice the alternate Spanish lettering and be puzzled by it. The manufacturers anticipate a certain normalcy on the part of the watch buyer; “normal” folks aren’t up at the hours when the watch does its little secret switch.

Satan depends upon the same sort of normalcy in dealing with human beings. Sometimes we give the old devil more credit than he deserves for knowing exactly how to tempt us, and when, and with what devices. No passage of Scripture suggests to us that Satan can read our minds or know what is in our hearts. Only God has such insight (Psalm 44:21; 51:6; Ecclesiastes 12:14; Hebrews 4:13). In fact, it is plain from what we see of Satan in the Bible that he cannot read minds: he misjudged the faith of Job, thinking that righteous man would curse God if robbed of his substance and health (Job 1:9-11; 2:4-5), and he believed Jesus could be tempted to sin by the desires of His human form and by carnal pride (Matthew 4:1-11).

No, Satan is not telepathic. But he is a keen observer of the human condition, of human frailty and weakness. Over thousands of years, he has had innumerable chances to try out various temptations on people, and he’s learned all too well what works. He knows what will work on me because he’s encountered millions of other people like me, and he recalls what got to them. And he’s watched me carefully enough to note those things that do not appeal to me, and those that do. Satan is a master of the scientific method — he forms a hypothesis about what will tempt a certain individual, he creates an experiment designed to test that hypothesis, he carries out the test and records the result. If something works, rest assured he’ll utilize it again and again. If something fails, he’ll try something different.

And he’s extremely tenacious: Satan never gives up. Even when Jesus staunchly resisted his wiles, the devil “departed from Him until an opportune time” (Luke 4:13). He left Jesus alone for a brief while, but he was right back after Him again the next time he saw what he thought might be an opening.

Satan counts on our normalcy. He depends upon us being exactly like all the other people he’s met over the millennia he’s been “going to and fro on the earth, and walking back and forth on it” (Job 1:7; 2:2). That’s why he has no temptation “except such as is common to man” (1 Corinthians 10:13). He doesn’t have the power to devise some trial especially for you. All he has to work with is what he’s used — and is using — on everyone else. Like the fisherman, who tries one kind of bait or lure after another until the fish finally start biting, Satan will hurl everything in his bag of tricks at us until something finally persuades us to sin. Then he’ll use that over and over again to keep us enslaved.

Don’t be “normal.” It’s what the devil anticipates. Instead, do what he doesn’t expect: “resist him, steadfast in the faith, knowing that the same sufferings are experienced by your brotherhood in the world” (1 Peter 5:9).