Renewal, the Brooklyn-based nonprofit organization that works to save lives through kidney donations, won’t work with just any hospital.

“The hospital has to have the same philosophy as ours,” said Rabbi Josh Sturm, Renewal’s director of outreach. “Donors need to be treated as heroes. The proverbial red carpet should be rolled out for them.”

While kidney donor Rabbi Shelley Kniaz of Teaneck — who donated a kidney at NewYork-Presbyterian/Weill Cornell Medical Center on Tuesday — says she was treated extremely well by hospital staff, she doesn’t feel like a hero.

“It’s a great thing to be able to do,” she said. “Quality of life and length of life is the gift you’re giving someone.” Not to mention the fact that during the long period of testing, “I found out that I’m as healthy as a horse.” And — as if this weren’t enough — her doctor told her she had a “beautiful kidney.”

But yes, she said, she did receive the royal treatment during the few days she had to stay in the hospital. “I had a single room, Renewal sent people to visit, with gifts, robes, and slippers, and they checked in a lot.” Not only that, but “the hospital has a fantastic staff.”

Renewal, now nearly 11 years old, has helped facilitate several hundred transplants. While the organization won’t turn anyone away, its waiting list is 95 percent Jewish.

“We’re a Jewish organization and we’re not embarrassed about that,” Rabbi Sturm said. “But with that said, our doors are open. We tend to stick within the Jewish community because it matches our skill set and we don’t have resources [to help] everybody.”

Rabbi Kniaz, the director of congregational education at Temple Emanuel of the Pascack Valley in Woodcliff Lake, reported after her procedure that “the incision is small and doesn’t cause a lot of pain at all.” During the procedure, her stomach had to be filled with gas; to relieve the discomfort this causes, now that she’s back home she goes for walks. In a brilliant move — which gives well-wishers a chance to visit with her while she gets in the walking she needs — she created an online signup sheet for walking partners.

“Renewal liked that,” Rabbi Kniaz said.

“Really, I’m not suffering,” she added, though it’s still a bit uncomfortable to stand up and sit down, she said. She described the surgeon who did the laparoscopic operation as “amazing” and pointed out that the hospital has done many such operations, “with an excellent track record.”

She has had no second thoughts about the donation. “After the euphoria lifts, you realize you have to face the recovery process,” she said. “OK, you say, it will take two weeks at least until I’m feeling like I can move normally. It’s just a matter of adjusting.” But unlike many patients, for whom surgery is not optional, “I had the benefit of feeling good about doing it.”

Rabbi Kniaz said that about eight years ago, Rabbi Ephraim Simon, the co-director of Friends of Lubavitch of Bergen County in Teaneck, donated a kidney, and it was “something that definitely piqued my interest.” Later, in 2015, Rabbi Larry Rothwachs, raised in Fair Lawn and now the religious leader of Teaneck’s Beth Aaron, did the same thing.

“It was on my mind, but it wasn’t in the cards then,” Rabbi Kniaz said. But about a year ago, friends from her own synagogue, Congregation Beth Sholom in Teaneck, started letting people know that they needed a donor. “I wavered at first, but six months later I casually asked them about it.”

The couple, Leon and Michal Lissek, told her about Renewal, so she called the organization and learned about the process. “They matched me with women my age who had done it so I could hear about the recovery,” she said. “They’re so happy they’ve done it. ‘I’m sorry I only had one,’ someone told me. ‘I would do it again.’”

“It was a long process, but Renewal really facilitates everything,” Rabbi Kniaz continued. At a recent educational and awareness session on kidney donation held at Beth Sholom, “I learned that in most cases where people donate, you may have to go in three or four times. But Renewal arranged that I could do it on one long day. They try to make it so you don’t have to wait around.”

The rabbi told the Lisseks that she was starting the testing process and that she would keep them updated. Her intention was to donate the kidney to Leon, should she choose to proceed. “I knew that it gave them a lot of hope,” she said. While she thought briefly about not telling them — in case she was disqualified or changed her mind — she ultimately decided that the issue was so pressing that she needed to be “very honest about it.”

In the meantime, she asked her husband, Rabbi Eliezer Diamond, professor of Talmud and rabbinics at the Jewish Theological Seminary, to have his kidney checked. “What will happen if you donate and then a family member needs it?” she said a social worker asked her. “Will you regret it?”

“I said, ‘Yes, but it won’t be debilitating. Hopefully, they can get the same help.’” As it happens, her kidney was not a match for Leon Lissek, but she moved forward and donated her kidney to someone else. In the meantime, a donor has been identified for Leon — one of his former students from St. Louis — and his transplant will take place in early August. “So he would have gotten one anyway. But during the six months they knew I was testing, it gave them a tremendous amount of hope.”

Rabbi Kniaz remembers that at one point she taught a session on live organ donation at a Melton Adult Program ethics course. “At the time, the risks were higher and the success rate was lower,” she said. “Now, there’s little debate. Jews can be really proud of how much we step up. Renewal’s goal is that people will not have to wait more than six months for a kidney.”

Not only has her Teaneck congregation been supportive, she said, but “I spoke to Richard Tannenbaum” — Temple Emanuel’s executive director — “from an employee point of view, and he told me he was sure that the board would say to take all the time I need.

“Not only did the shul provide a meal this Shabbat but the Sunday morning minyan sent flowers and nice messages.”

Why did she do it? “Leon Lissek is an extraordinarily sweet person,” Rabbi Kniaz said. “Everyone will tell you that. He’s talented, a Holocaust survivor, warm, loving, with a beautiful neshama.” She has known him as a Beth Sholom fellow congregant for more than 15 years. And when she was well into the testing process, she remembered that many years ago, at home in Madison, Wisconsin, she had taught a boy who grew up to become his son-in-law.

For his part, Cantor Lissek — who served Congregation B’nai Amoona in St. Louis, Mo., for some 30 years — calls Rabbi Kniaz “an angel.” He also uses that term to describe the woman whose kidney he soon will receive. That second donor, whom he once taught when she was a child, is the daughter of the man who was president of B’nai Amoona when he worked there.

As a survivor, with difficult memories of his youth, “I got to appreciate good people as I got older,” Cantor Lissek said. “I have encountered many good people being a cantor. The world is made up of angels and good people.” Rabbi Kniaz, he said, not only saved his life — when she agreed to donate her kidney he was moved to the top of the recipient list — but she also saved the life of the young woman who ultimately received her kidney.

While Cantor Lissek is a bit apprehensive, “I think it will be wonderful,” he said of the upcoming transplant. “I’ll do everything the doctor tells me to do.” At the age of 81, he is in good health, walks 45 minutes a day, works with a personal trainer, and “eats the proper food. My numbers are pretty good.”

In addition to insisting that hospitals treat donors with special care, Renewal works only with hospitals “with which we are comfortable,” Rabbi Sturm said. The organization requires that the hospitals have a lot of experience with the procedure. He cited Mt. Sinai, for example, “which does 200 a year.”

When people call Renewal for help in securing a transplant, “we ask they what hospital they’re working with,” he continued. “They need to be registered at one of the hospitals we work with. I wish we had a refrigerator full of kidneys, but we don’t. We go over with them what we can provide.”

What they can offer is “marketing and strategy to help the patients be able to market themselves and hopefully find a kidney donor. We get them to the finish line. Our donor coordinators hold their hands through the arduous process.” The marketing Renewal provides includes the use of an in-house design person to create fliers, set up a Facebook page, and so on. The goal is “to get the word out there. The more proactive people are, the greater the likelihood of finding potential donors.” Rabbi Sturm often speaks at educational programs such as the one Beth Sholom held. Not only are these program helpful in themselves, he said, “but they may provide multiple potential donors.

“Some donors walk in off the street,” he said. “I wish the numbers were larger, but probably two dozen come in every year.” Still, he said, those people only dent the list of people waiting for kidneys. When Renewal was created, “we wanted to do one transplant a year.” The next year, the organization doubled its goal to two. Last year, Renewal arranged 67 transplants.

Rabbi Sturm said the number of people requiring kidneys has been increasing dramatically, though he can’t say for sure why that is. “I’ve spoken to different doctors,” he said, citing the reasons they suggest. First, the top few causes of kidney failure include high blood pressure and diabetes — and we are seeing an increase in the number of obese Americans. Second, given a technical change in how medical conditions are classified, more people are allowed to be placed on a waiting list. Third, with dialysis able to extend life at least for five years, some potential recipients who in earlier years might have died while waiting for a kidney stay on the list much longer.

Rabbi Sturm said that the average age of donors is the mid-40s. Interestingly, his organization has seen the inverse of national statistics, which show that women donors outnumber men. The minimum age for donation is 18, “but we haven’t had anyone below the age of 21,” he said. “We don’t feel they’re of the right mindset.” While the maximum age is 70, the group had a donor who was 71.

“In the United States, over 97,000 people are on waiting list, and only about 16,000 to 17,000 transplants happen each year,” he said. “About five thousand to six thousand people die while on the waiting list. It continues to build up.

“Back 28 years ago, in 1989, the waiting list was 18,000; now it’s about 100,000.” Some of those on the list are children, “but it’s amazing the way God created the human body. A child’s body can take a larger kidney.”

Why should people become donors? Kidney donation “offers an amazing opportunity to literally save a life,” Rabbi Sturm said. “There’s nothing more special than doing that.