C.S. Lewis was a sinner, and those are not my words, but his. He smoked and drank with enthusiasm, habits that might have contributed to his death of kidney failure on Nov. 22, 1963 — the same day that John F. Kennedy died.

Lewis loved going to bars, drinking beer, and talking about books with his good friend J.R.R. Tolkien. As such, I’d always figured the dialogue of demons in “The Screwtape Letters” was born over a couple of pints, but The C.S. Lewis Institute says the idea came to him as he was leaving a church service. The pastor had apparently delivered the kind of sermon that causes one’s mind to wander. Good things can come from bad homilies.

“Screwtape” itself is a merry riot of a sermon, in the form of letters composed to a demon-in-training named Wormwood from an older, wiser demon named Screwtape, who always signs off “Your affectionate uncle.” In the letters, Screwtape offers encouragement and advice on how to keep Wormwood’s “patient” from becoming a Christian.

In one passage, for example, Screwtape suggests that Wormwood can induce his patient to stay in a bad mood by encouraging him to think of his time as his own, and not something that belongs to “the Enemy” — the almighty God. In another, he exhorts Wormwood to encourage the patient to think that any religious sentiment he experiences is just a phase that he will pass through:

“You see the idea? Keep his mind off the plain antithesis between True and False. Nice shadowy expressions — ‘It was a phase.’ — ‘I’ve been through all that.’ — and don’t forget the blessed word ‘Adolescent.'”

Uncle Screwtape has the kind of voice that can get into your head, and for fun one Saturday morning, as I was procrastinating doing one thing or another, I imagined my personal Screwtape letter: what the old schemer would advise the young demon assigned to me.

My personal Wormwood spends a lot of time suggesting that I need to check Twitter to see if there is something pressing happening in the world that needs my immediate attention, even though this has NEVER ONCE BEEN TRUE.

He also spends a fair amount of time suggesting that I should dispense with this whole silly running business and flop down on the couch BECAUSE I AM TOO OLD FOR THIS NONSENSE.

Like so:

My dear Wormwood:

I note what you say about your patient, how she is has been running for almost four decades, and so you despair of getting her to stop. But it is the concerning length of time that works in our favor. Focus on that.

Make her believe that she’s too old, that she looks ridiculous, that it’s ruining her knees, that it’s taking time away from other, important things; that the whole sweaty enterprise of nearly 40 years has netted only a few glorious moments and a mountain of sundry aches and pains. Point out the bunion, and the bunion-to-be. The blisters that threaten to erupt in another mile or two. Whisper that the cost of road races have doubled, and that the whole idea of racing is ridiculous (paying to run on public roads!), and that she will never win an award, even in her age group.

Point out trouble of getting to a start line on a Saturday morning, even if it’s just 3 or 4 miles away, and the terror of not knowing where the next Port-a-Pottie is. Tell her those knees should really not be seen in public. Remind her that she once somehow gained a pound after a half-marathon. And that she once wandered into, and ran, the WRONG RACE. She’s not, after all, the brightest bulb on the planet.

Make her believe that she is a morning runner and if she doesn’t get out within those magical hours of 7 and 9 a.m., that she will just have to skip that day. Wrack her with anxiety about junk miles versus running streaks, cold plunges and saunas, carbs and keto. Keep her spinning from one set of advice to the opposite, never knowing which to follow. And most of all, keep her away from anything written by Dr. George Sheehan.

Your affectionate uncle, Screwtape

I highly recommend this exercise, which is the equivalent of calling out “Excuses, assemble!” and getting them all in one manageable corral, where you can then stick them with pitchforks of mockery. Maybe it will help shrink your demons, as it does mine.

Lewis opened “Screwtape” with a Thomas More quote: “The devill . . the prowde spirite . . cannot endure to be mocked.” Truth.

Eleventh in my age group and ridiculously proud of it. Thus I refute Beelzebub.