Last year around this time my son, who apparently is quite thoughtful between video games, asked me about a song the kids sang at his sister’s preschool Christmas pageant. “We will tell the world that the Lord is come,” the song goes, and I told him yes, I remember, that’s “Mary Had a Baby.”

“It’s kind of an ironic song, isn’t it?” he asked me.

“Really?” I replied. Irony isn’t a quality I usually look for in a Christmas carol, but perhaps something slipped past me.

“Well,” he explained, “They told everyone that Jesus was born. And then once everyone knew, they killed him.” They shouldn’t have told anyone, was his point, and I think he may be on to something.

If your divine savior is going to take human form, and become mortal, then alerting people to his advent is probably the last thing you want to do. Instead of telling it on the mountain, aren’t you better off keeping the whole thing under wraps? You know—pay off the wise men, put the shepherds into the Witness Protection Program, and send out a press release telling people, “Calm down, that star everyone noticed the other night was actually a weather balloon.”

It’s true that this approach would have resulted in really different Christmas carols than we have now, with more of a nothing-to-see-here-move-along kind of vibe. But just think how much more thrilling the story of Jesus’ life would be if his real identity had been kept a secret. I’m not saying he couldn’t act like the Son of God. He could still do miracles. But he’d wear a mask. Like Batman. Or a Mexican wrestler.

OK, maybe that would change the story too much. But anonymity would certainly have been safer for the infant, human Jesus. Because if any one thing defines the human condition, it’s our vulnerability. In fact, the more you learn about defending the human body, the more you realize what a hopeless task it is. These forms we inhabit are little more than a collection of vulnerabilities. All we are, practically, is weak spots. You can’t possibly defend them, not completely.

It’s a testament to our species’ impatience that we have to think up ways to hurt one another. Fists, weapons, spankings, crucifixion—it’s all overkill. If you wish someone harm, all you need to do is wait a bit. Odds are that something or other will get them before too long. But people were every bit as impatient back in the days of King Herod and Caesar Augustus as they are now. It’s kind of surprising Jesus survived into his thirties, the poor schlimazel.

I grew up reciting the Nicene creed, which relates how Christ came down from heaven, and after some not entirely clear interaction between the Holy Spirit and the Virgin Mary (the Second Ecumenical Council was pretty vague about it), he became man. I’ve often wondered if Jesus really knew what he was getting into when he signed up for this. It must have been something like having your dad tell you he’s buying you a new car for graduation, and it turns out to be a Pontiac Sunbird. I don’t know about you, but I’d be pissed.

Because it’s hard to imagine anyone voluntarily trusting their immortal soul to this poorly-designed vehicle. Anything can kill us humans, and it does, with depressing regularity. We are vulnerable to extremes of heat and cold; to dehydration on one hand, and drowning on the other; to high voltage and low air pressure; not enough oxygen or even too much of it. Many substances are poisonous to us and we seem to develop a taste for a lot of them. We can be killed by sharp corners, blunt objects, excessive speed, heavy machinery, and gravity. The truth is that humans are vulnerable in so many ways that it’s a wonder we don’t just drop down dead in our tracks on our way to work every morning. A lot of people do.

So Jesus is born into this body that’s basically one big design flaw—in an era with little understanding of sanitation or medicine, to boot. And on top of all that, a lot of people actively want to kill him.

Now my grasp of theology may be appallingly superficial, but I know quite a bit about how to hurt people. If you’re looking to harm a human in a hand-to-hand situation, you have at least a dozen excellent options even if you’ve never studied martial arts or boxing or anatomy. Identifying these basic targets is usually part of a good self-defense class; one common exercise involves naming the most accessible targets on the human body, from the top down: Temple, eyes, nose, throat, floating ribs, groin, knees, shins, feet.

If you want to get more specific you can go on to describe the potential injuries associated with each target: Blows to the front of the head can damage motor areas of the brain; blows to the temple can break the sphenoid bone and sever the temporal artery; a little lower and you can break the cheek or damage the meningeal artery. Attacks to the eye can blind, of course, and if you get all the way through the eye with a weapon or even a finger (please don’t try this at home), you can damage the brain. Blows to the front of the face can break the septum or eye sockets, fracture the upper jaw, and damage nerves. Any blow to the head can cause concussion and brain damage.

If you’re too short to reach your opponent’s head, you have plenty to choose from in the neck and throat. The jugular vein and carotid artery can be crushed. The Adam’s apple can be shocked, as can a veritable bouquet of other important nerve centers—vagus, phrenic, laryngeal, hypoglossal—any one of which can lead to asphyxiation.

Feeling vulnerable yet?

Moving still lower, you can break the collarbone, fracture the ribs, damage the liver and spleen (you probably need elbow attacks to get in there deep enough), rupture the kidneys, and radically reconfigure the groin in so many unattractive ways that I don’t think they’re worth enumerating here.

Expanding our options laterally, the arms and legs may not seem very vulnerable but they are rife with readily accessible nerves, veins, and arteries, any of which can be damaged to lasting effect. And I’m not even going to consider pressure points, the body’s physiological reset buttons, which experts can activate with pinpoint precision. Knees are incredibly vulnerable, as anyone over six feet tall can tell you, and the foot is full of small crunchy parts.

There are targets on the back too, though we usually spend less time discussing them in self-defense classes. If you’re behind your attacker, he’s momentarily unable to hurt you, so running is probably going to be your best option. I’ll just point out that the spine, tailbone, and back of the neck aren’t exactly armor-plated.

In other words, whether you want to hurt someone a lot or just a little, the buffet is open. That’s what it means to be human. So welcome the infant Jesus! Even if you don’t know how his story ends, you can tell the kid is pretty much doomed. Just like the rest of us.

Yeah, I know, the Resurrection supposedly changes everything, but I have to be honest. Much as I love a happy ending, I’ve always had my doubts about Jesus’ brief post-mortem reappearance. It strikes me as a clumsy narrative coda to a story that’s more instructive in its simpler form: Someone tries to get people to treat each other better, and people respond by brutally and publicly destroying him. The End.

The fact that Jesus gets to come back to life after his execution distracts us, I think, from the more obvious truth: Any one of us can be killed with relative ease. And people like to kill one another. It’s not the uniqueness of Christ’s execution that ought to impress us. It wasn’t just that this time, they happened to pick the wrong guy to kill—the one with friends in high places. To me, the Crucifixion matters precisely because it was so commonplace. Honestly, do you have any idea how many people the Romans crucified over the years? Nobody knows. They didn’t even keep count. Thousands, hundreds of thousands, probably. They did it to everybody. It was like getting a parking ticket back then.

Think about that—all those thousands of people who, just like Jesus, were once tiny adorable babies. Somebody—a whole bunch of somebodies, with a plan and a government and an army to back them up—put nails through those people’s hands and feet, hung them up on specially built crosses, and left them there to die. In front of an appreciative audience.

What I think Jesus’ death proves is that whether or not the human race has ever had a savior, or ever will, we sure as hell need one.

I have no idea why we’re so vicious or why, if we must be vicious, we also have to be so heartbreakingly vulnerable. But neither can I come up with a good alternative. Would we really treat one another better if we were invulnerable? I don’t think so.

This is supposed to be a season of hope, so let me share with you what little I have. If you spend much time learning how to damage the human body, and teaching other people how to do it, and practicing the application of that knowledge, you gain a new appreciation of how vulnerable you are. That’s not so pleasant. But you also come to understand the great equalizing force—almost the democratic nature—of weakness.

People can be strong in different ways, depending on their age, gender, size, and fitness level. But the weaknesses of the human body are remarkably consistent from person to person. Exposed nerves, limitations of joint movement, the pull of gravity—those don’t change much regardless of how you’re built or how strong you are. Humans can be incredibly selfish, but we share our weaknesses. We have no choice. Our vulnerabilities link us, whether we like it or not. They make us human, and individually mortal, but they also make us part of humanity.

A lot of our energy—in karate, business, life—is invested in making ourselves stronger. But you can’t make yourself invulnerable. And no matter how strong you are, you never know if you’ll be stronger than your opponent. So focusing exclusively on your own strength is shortsighted, even if your goal is simply to protect yourself. You must honestly confront your weaknesses. When you learn about your own vulnerable points, you also learn your opponent’s. This gives you a decided advantage in a fight. And it gives you something else too: It gives you a sense of why you should avoid fighting if you can. We fight over differences; our weaknesses remind us that the similarities are more important.

Not exactly tidings of joy, perhaps, but I do find some comfort there.

Peace to you and yours.