Korach was a rebel. Not just any rebel, but one who rebelled against the preeminent Jewish leader, Moses. Yet rather than living in infamy, an entire Parshah of the Torah is dedicated to him and even named after him. Why, couldn’t we find a better name for this Parshah? Must we immortalize Moses’ greatest detractor by recording his story for posterity and naming a Torah portion after him?
When the Soviets came to power, they changed St. Petersburg to Leningrad because they didn’t want an iconic Russian city named after an iconic Russian Czar. When Communism fell, Lenin’s name was removed just as quickly. No one wants to name a street or a city after a traitor. How much more so a Torah portion? Remember the images of Iraqis tearing down statutes of Saddam Hussein as soon as he had been ousted? That is the normal modus operandi. Why is the Torah so different?
Some people say that it is because the Torah never whitewashes our sins. Yet, I have a hard time accepting that this is reason enough to award a terrible rebel by naming an entire Parshah after him.
The Defining Feature
Allow me to suggest an answer that only becomes obvious after it is presented. Our question assumes that Korach’s defining characteristic was rebelliousness. Yet, that is only one part of his life story. Korach was a son, a husband, and a father. He was a leader of the tribe of Levi. He had been loyal to G-d and to the Torah throughout the difficult years of the exile in Egypt. There must a hundred, if not a thousand, good things about Korach.
As a member of the tribe of Levi, Korach did not worship the Golden Calf. He remained loyal to G-d despite all the turmoil that went on at that time. Korach’s name was not mentioned in connection with the report of the spies about Israel. It stands to reason that he rejected that report too. Yet, when his name is mentioned, we think only of the rebellion. Granted, it was a big rebellion. And it was his last act—he died in the process, so he never had a chance to repent. Yet, that is only one part of his story.
There is an amazing lesson here. Even when we know for certain that someone committed a terrible sin, we ought not define him or her by that one act. It is only one part of their being. They are not entirely bad. If you had to break it down, you could assume that people are mostly righteous. They have one or two temptations that are hard for them to overcome, and they fail in those areas. But all in all, they are good people that failed. They are not bad people that happen to have a few good strengths.
The Optimist View
This is an optimistic view of our fellow. Some people love to tear others down. A proper Jewish perspective is to lift others up. Yes, even the sinner should be lifted. After all, people tend to live up or down to what we expect of them. If we focus on the positive, they will live up to our expectations. If we focus on the negative, they will live down to our expectations.
Even a self-hating Jew, who doesn’t believe in G-d, who never set foot in a synagogue, fasted on Yom Kippur, or lit a Chanukah candle. Even the Jew who stands with our enemies and marches in solidarity with those who hate us, has a redeeming factor. No one is all bad. Even if they are ten or five percent good, that is enough to build on. If he is five percent good today, he can be a hundred percent good tomorrow. We need to give him a chance. We need to believe in him so he can believe in himself.
There is a philosophy among some Jews that sinners must be ostracized and called out. That sinners must be shunned and avoided. I say that sinners must be embraced because they are only sinful in the areas of life in which they sin. In the rest of their lives, they are righteous.
Let me give you an example. What comes to mind when you think of Adam after he ate the forbidden fruit? The first thing most people think is that Adam was a fickle sinner with little discipline. Some people are more charitable and think of Adam as a penitent since he repented for his sin. Yet, my mentor the Lubavitcher Rebbe once said that Adam was nearly entirely righteous. He was only a penitent for one sin, but in the rest of his life he was a perfect Tzadik. Perfectly righteous.
This is a revolutionary way to think of a sinner and even a penitent. Don’t look at the ten percent that is less than good. Look at the ninety percent that is stellar. And if the numbers are not as good as that, the principle still applies. Believe in your fellow and your fellow will believe in himself.
But what of the sin itself? We can’t live in denial and pretend that the sin never happened. We can’t rewrite history, right? The answer is that we are not trying to rewrite the past. We are trying to change the script for the future.
The past happened and it never should have. There is no excuse for sin no matter how strong the temptation. Yet, ask not, why did he sin? Ask, what can be done about it now?
And the answer is, repentance. It is your Mitzvah to tell this Jew in whom you believe and whom you love: G-d never wanted you to sin, but now that you sinned, G-d has a task for you—a Mitzvah that you could never had performed had you never sinned. It is the mitzvah of teshuvah—repentance.
Transform your sin into a powerful motivation for change by making absolutely certain that you will never slip up again.
Think of a dam that is placed in the river. At first it acts as a restraining force that stops or slows down the current. This is clearly not good for the river. But once the dam is built, a new opportunity arises. It can be used to generate electricity or to power a mill that the original current could never have.
It is never a good thing to slow down a river, but one it is slowed, the question is, what now? Should we remove the impediment or take full advantage of it? The same is true of a sin. It is never good to commit a sin. But once we have sinned, the question becomes, what now? Should we act as if the aberration never occurred, or should we use it to generate a kinetic force that will catapult our relationship with G-d to a whole new stratosphere? The answer is the latter.
A penitent has something that the righteous person can never have: desperation to make up for lost time. A distance that he must make up for with an all-out sprint. A gap that he must jump. The penitent has no patience. The penitent is in a rush; in an all-out sprint toward G-d with unbounded energy. He is in a state of perfect velocity, he is in full momentum, as he rushes headlong toward G-d. The distance generated by sin creates an opportunity. It gives him a passion that he never had before.
This is why an entire Parshah was named after Korach. Ninety percent of Korach was good, not bad. And the ten percent that was bad, serves as a lesson to us. All is not lost after sin. The path to repentance is open and repentance makes us better than we could ever have been before.
This Shabbat marks the 28th Yhartzeit of Rabbi Menachem Mendel Schneerson, the Lubavitcher Rebbe of blessed memory. His love for, and supreme confidence in, every Jew was legendary. He created a world-wide movement of inspiration that is bringing Jews back to G-d. On this day, let us be inspired to take his loving view of our fellow Jew. No matter where they are on the ladder of Torah, let us encourage them to take one more step. Up. 
 This essay is based on Likutei Sichos 17, p.6 and Sefer Hamaamarim 5732 5733, p. 439.