There is no emotion, there is peace.
There is no ignorance, there is knowledge.
There is no passion, there is serenity.
There is no chaos, there is harmony.
There is no death, there is the force.

This is the mantra that the Jedi Order lived by until very recently in terms of galactic history. It has served as a guiding beacon that provides all Jedi with an ideal to strive toward, the most important foundation of any doctrine. Over the years, the code has been the subject of endless debate. Its interpretations have varied innumerably, and its supposed fallacies have been the reasoning for the fall of many a young Jedi student.
In the current age, it seems that most force users have foregone the code as the relic of a bygone era. They see no value in its teachings; they find it archaic and restricting, for all beings wish the glory and adoration of good deeds without having to make the sacrifices required to forge good character in an individual. I aim to dispel whatever notions the reader might have on this topic.
To begin, the Jedi Code is meant to be a guideline, not a strict way of life. Jedi in the past grew to believe that it was so, and in doing so damned the Order to several hundred years of infighting, destitution, and eventually near eradication. To take the code as a plan to live one's life behind entirely is to deny oneself their humanity, or whatever the equivalent might be for another species: what makes us living creatures.
The code is meant to be something we use to center ourselves. It is something we call upon in times of crisis, when we need clarity, or when we simply wish to disconnect with the situation and make a purely rational decision. It is a tool, much like our lightsabers, or a comm link, and if purely used will bring you no benefit.
I will expound upon the first line: there is no emotion, there is peace. A Jedi must always strive to find his or her center. Our ability to work with the Force is greatly diminished when our minds are not empty of doubt. The heat of anger only serves to make us unfocused, and open our minds to degenerate paths we would otherwise abhor.
To ascend beyond emotion is a Jedi's greatest test. We must master our emotions, and learn when they should be expressed, and when they would only do us and those around us harm. In combat, a Jedi must empty their mind of all things. We must aim to achieve a moving meditation, our minds becoming so intrinsically linked with the empyrean that we move without thought. In times of diplomacy, we must purge ourselves of our emotions to serve as a truly fair arbitrator. We must learn to cast aside greed and desires for glory in exchange for clarity of mind. Only then can we make a truly fair, informed, and moral decision.
An extreme case would be a matter of mass death. Say two worlds were about to fall. One of these worlds is populated by several billion people, and your fleet is supplied well enough to ferry them offworld before their planet is annihilated. Their sister moon is home to only a few thousand, but flying the fleet there will take just as much time as the first world, and you only have enough time to save one of them. The catch is that your family lives on that moon. Everyone you've ever loved or known is stuck on that rock spiraling toward oblivion. This event is terrible and disastrous, but as Jedi, we are trained to make the right choice.
The utilitarian decision, the one that would bring about the greatest good in terms of how many people are affected, would be to evacuate the first world. A Jedi must be ready to sacrifice everything for the greater good, including their lives if necessary. We must master our emotions, so that even in these moments of emotional chaos, we stand at the center, and we make the right call. It is a tragedy that thousands of people have died, and your life may be in ruins with the loss of your family, but the loss of billions would be an apocalypse. This is the path Jedi walk. Our is one of silent suffering, but we are proud to walk it, because we know our lives had meaning for every soul we helped along the path.
The second line: there is no ignorance, there is knowledge. This is a far more straightforward section of the code. It is simply the understanding that knowledge is the key to progress and happiness for all sentient life. Once something is understood, it is no longer feared. We can use knowledge to prevent any further tragedies that entity might bring about as well. The greatest benefit of a search for knowledge is the growth of the self, both spiritually and mentally. Thus it is that all Jedi are forever students, always learning, always keen to open their eyes to a new side of the galaxy.
The third: there is no passion, there is serenity. This like the first is one of the more controversial lines, and often something that has been cited as the reason Jedi have turned to Sith teachings. It is the result of poor teachers and small minds that this section of the code is so often misrepresented. In stating that there is no passion, the code instructs that a Jedi empty themselves of hotheadedness and overwhelming emotion that may cloud their judgement. It is not instructing its followers to forsake love, craftsmanship, hobbies, or anything else that makes people what they are. It only seeks to inform the student that they must master the technique of casting aside passions in times of service.
Love is powerful, it is the Ashla in its purest form, but it can be blinding when duty is required. One must learn to compartmentalize this, to set it apart in their mind when acting as a Jedi so that they may, as stated before, be a fair and moral arbitrator. Beyond that, the greatest of passions is hate, and hate is the antithesis of the Ashla. Hate is the passion we guard against so dearly, for hate in the mind of a force sensitive is more powerful than any hallucinogen, more intoxicating than any aroma. It is hate, and its sister dominance that the code wishes us to guard against. These emotions must be absent from the heart, for they will only fester in the dark corners of the mind if left unchecked.
The forth: there is no Chaos, there is harmony. The galaxy functions in an ever-shifting balance. Its cycles of life and death are predetermined, their details so minutely forged that a sentient mortal's mind boggles in its attempts to understand. This is the Light, a constant cycle of give and take, where no resources are wasted, and all who need them receive them. That is the harmony we seek. The Chaos is indicative of the Bogan. It is the molestation of this cycle, the perversion of the delicate balance. This is why we must fight the Dark Side wherever it rears its head, and watch for its corrupting influence in our peers. Just as there is harmony in the Light, so too must there be harmony in the Jedi. Where there is no harmony, there is only Chaos, and a Jedi cannot do his or her work with such impairments.
We exist to serve the balance, the Sith exist to destroy it.
The final portion: there is no death, there is the Force. This is the simple truth of the galaxy that the earliest Jedi understood, but so few today do. Death is a fleeting and temporary experience. Our souls are cast into the cairn after death and judged for our deeds. In my research, I have determined that those of good spirits and moral standing often merge entirely with the energy field that is the Force, and that life force is reborn shortly thereafter in the form of a newborn child. Those that follow darker paths often find themselves cast into the shadowy corners of the Netherworld to suffer for eternity, and some of the more moral spirits still find themselves manifesting in this realm, or pocket realms of it. Even still, a handful of individuals have managed to retain their ego after death, persisting as spirits that we refer to as Force Ghosts. What happens to these beings after they leave our material plane? I have no idea, but one day I hope to join their number and find out for myself.
That is the Jedi Code as I best understand it. I hope I may have opened the eyes of some, though one must respect all interpretations of the code, so long as they are not forged in ignorance. After all, there is only knowledge.