I’m Jay Bhattacharya. Most of you probably already know me, so I probably don’t need to introduce myself too much. I teach in the medical school at Stanford, and I wanted to talk about clean and unclean because I think the Bible says a lot about that.

I’ll start with a little story from when I was much younger. I’ll begin by telling you a little about medicine. If this were a medical school lecture, I would have pictures on the screen, but I’m going to spare you that—you should thank me for that.

Leprosy is a disease caused by bacteria from the same family as tuberculosis. This disease has a long and sad history dating back to ancient times. Even today, hundreds of thousands of people around the world come down with leprosy every year. It’s not a disease of the past; it still causes suffering today.

When the infection takes hold, the first signs are easy to ignore or miss. Small white plaques appear on the skin, and if you touch them, the skin feels numb. Doctors track the disease with a very sophisticated device—a safety pin. You take a safety pin and check if the person feels numb.

When I was a young medical student, I spent a summer on a mission trip working in a small hospital near the border of Odisha and West Bengal in India. The hospital had three very dedicated doctors managing the medical needs of the rural village nearby. The population was poor, and people there suffered from many diseases uncommon in the United States.

Once a month, the doctors would drive about 50 kilometers to staff a clinic dedicated to treating leprosy patients. Patients would come from all over the province, arriving on foot for treatment and assessment. The disease still carries a stigma, so the clinic’s name didn’t actually mention leprosy. Instead, it used a different name to avoid the stigma—it was called Hansen’s Disease, named after the doctor who first discovered it in 1873. In fact, it was the first human disease known to be caused by bacteria.

If untreated, the disease progresses steadily. Small plaques become larger and larger. Again, I’m going to spare you the pictures—you don’t want to see them. The bacteria destroy the sensory nerves that supply the skin. The disease itself doesn’t necessarily cause disfigurement; rather, patients lose feeling in their fingers, toes, and feet. There are stories of lepers touching hot stoves without realizing they had burned themselves. Because they can’t feel pain, they suffer injuries and infections that ultimately lead to the loss of fingers, toes, and more. That’s why leprosy is associated with disfigurement.

The good news is that the disease is treatable. Since it’s a bacterial infection, it can be cured with antibiotics. The bad news is that you need very strong antibiotics—multiple antibiotics—for more than a decade. Even after patients improve, they have to keep taking antibiotics to prevent the bacteria from developing resistance. So these patients return to the clinic every month for their medications.

When I visited the clinic, I had the opportunity—again, I was very young then—to meet with patients. The doctors taught me how to assess the plaques using a safety pin, marking changes to track progress. Gloves were scarce in that rural village, so the examination was done without gloves. The risk of transmission was actually very small. Although no one knows for sure how leprosy spreads, most scientists believe it’s transmitted through respiratory droplets, like tuberculosis. It seems to require long periods of close contact to spread, so short interactions with patients posed a very low risk.

However, there has always been a strong stigma around the disease. In ancient times, as we heard in the reading from the Bible, lepers were ostracized. That stigma still exists today. On the way to the clinic, the doctors told me how important it was that we, as medical staff, showed no fear of the disease or repulsion toward the patients. If the physicians showed hesitation or disgust, the people in town might start fearing the leprosy patients, leading to demands that the clinic be relocated.

The story of Elisha and Naaman in 2 Kings hints at this stigma. Naaman was a powerful general, loved by the king of Syria. He had money, power, and status. But he was a leper. Despite his high position, his disease made him socially low. He was so desperate for a cure that when he heard a rumor from a Jewish slave girl about a prophet in Israel who could heal him, he asked the king for permission to visit—even though Israel was an enemy of Syria.

Elisha, the prophet, was a thorn in the side of the Syrian king. He often foiled the king’s plans by predicting where Syrian attacks would happen. So when Naaman asked for permission to seek Elisha’s help, it created a politically tricky situation. The king of Syria valued Naaman, so he wrote to the king of Israel, asking him to introduce Naaman to Elisha.

Naaman arrived at Elisha’s doorstep with gifts, money, and lots of stuff. But Elisha refused to meet him. Instead, he sent a servant with a simple message: “Go wash in the Jordan River seven times, and you’ll be clean.”

Why didn’t Elisha meet him? Was he afraid of catching the disease? Lepers were ceremonially unclean, and touching one meant undergoing cleansing rituals. Maybe Elisha wanted to avoid that. Or maybe, and I think this is the right explanation, Elisha wanted to show Naaman that God’s power didn’t require a dramatic display. Naaman expected a magic spell—something impressive. But Elisha just gave him simple instructions: “Go jump in the river.”

At first, Naaman was offended. The Jordan River wasn’t even a particularly impressive river! But after some convincing, he followed Elisha’s instructions, and he was healed. In response, Naaman rejected his old gods and followed the God of Israel.

Now, I want to contrast this story with how Jesus treated lepers. Jesus didn’t just say, “Go wash in the river.” He physically touched the lepers who asked for healing. This was shocking. Lepers were ceremonially unclean, and touching them made a person unclean as well. Ancient people didn’t know about germ theory, but they understood that leprosy spread through contact. Yet Jesus touched them anyway. His touch was a revolutionary act.

It shattered the idea that someone’s medical condition made them unclean. The usual theological formulation is that sin makes us unclean before God. That’s true—our natural inclinations are to do our own will rather than God’s. But Jesus’ physical act of touching lepers suggests that cleansing is not just spiritual; it’s also physical. Following Christ means not treating anyone as unclean.

Becoming a doctor requires overcoming the instinct to recoil at disease. Students have to unlearn their fear of blood and bodily fluids. Anyone scared of blood? (If you didn’t raise your hand, you’d make a great doctor.)

Christians, too, are called to set aside their fears and embrace compassion for the sick. Of course, God gives this gift more to some than others, and it’s not wrong to feel discomfort. But we must push past it.

I didn’t intend for this sermon to be about COVID, but I have to mention it because I think our culture has failed to follow Jesus’ example. From the beginning of the pandemic, society divided people into “essential” and “non-essential.” Healthcare workers and grocery store employees were “essential,” while others worked from home. I received emails from doctors and nurses asking if it was safe to hug their spouses because they feared they were “unclean” from treating COVID patients.

When someone gets COVID, what’s the first question we ask? “Where did you get it?” We treat contracting the virus like a moral failing. People with COVID are seen as unclean.

Did anyone ever forget their mask while walking outside and see a masked person jump into the street to avoid them? That happened to me. But the risk of transmission outdoors is very low. The reaction wasn’t about science—it was about the perception of “clean” and “unclean.”

Of course, we should follow public health guidelines and protect the vulnerable. But as followers of Christ, we must also erase the false distinction between clean and unclean. Sometimes, we are called to touch the lepers of our time—both literal and metaphorical—because Jesus taught that we are all unclean and equally loved by Him.