In Star Wars: Attack of the Clones, when Anakin loses his lightsaber, Obi-Wan chastises him by saying, “This weapon is your life.” While he is speaking practically, Obi-Wan also perfectly describes the symbolism behind a Jedi’s lightsaber.
Lightsabers represent much more than combat to Jedi, who are on the path to mastery of the Force. They are also a rite of passage and a badge of honor. Lightsabers symbolize the status of Jedi and their commitment to serving the will of the Force.
Kyber crystals are the key component for every lightsaber. They create the blade by focusing energy from the Force. For younglings, finding a kyber is a monumental day and the first step to becoming a true Jedi. On a ceremonial trip to the planet of Illum, Jedi younglings participate in an event called the Gathering where they must enter the Crystal Cave in search of their very own kyber. Within the cave they must face unexpected challenges and conquer their own fears, and only while trusting the Force to lead them to a crystal can they succeed.
By emerging from the cave with a crystal, the younglings prove that they have learned to listen to the Force for guidance. Finding the crystal is an important rite of passage that shows that they are prepared to start a new phase in their training. They can then begin to build their own lightsaber.
The process of building a lightsaber is very complex, and there are no instructions for exactly how to do it. They all have the same basic internal components: crystal, blade emitter and power cell, though some are quite unique. However, a lightsaber cannot be built by hand. While meditating, a Jedi must construct their lightsabers with the help of the Force because everything must be aligned perfectly or the lightsaber will explode when activated. This is why successfully constructing a lightsaber is one of the tasks that Jedi younglings must complete in order to become Padawans.
A completed lightsaber is like a badge of honor for Jedi trainees that shows their connection to the Force and the objects around them. The process proves their readiness to proceed to the next step in their training - apprenticeship under a Jedi knight.
Once Jedi complete their lightsabers, there is a special bond between weapon and wielder. The lightsaber acts like a conduit between the Jedi and the Force because the crystal focuses the energy around them, connecting each Jedi to the Force in a unique way. An old Jedi mantra from The Jedi Path manual states:
“The crystal is the heart of the blade.
The heart is the crystal of the Jedi.
The Jedi is the crystal of the Force.
The Force is the blade of the heart.
All are intertwined: the crystal, the blade, the Jedi. We are one.”
Since they are so interconnected, using their lightsabers helps the Jedi form a closer relationship with the Force. This is why Jedi Padawans learn to spar with each other. The harder they train themselves, the less control they have and, consequently, the more they allow the Force to flow through them and take over their movements. So, when they use their lightsabers, they are developing their faith in the Force. Training, however, does not stop when Padawans become Jedi knights. Learning to let go and trust the Force is a commitment that lasts a lifetime. Every time the Jedi see their lightsabers, they are reminded of their commitment to the Force and their journey to the status of Jedi.
This is what Obi-Wan meant when he told Anakin that his weapon is his life. He was reminding him of everything that the lightsaber stood for, especially his commitment to trusting in the Force.
Years later, Obi-Wan unfortunately had to emphasize his point in Revenge of the Sith. After winning their duel on Mustafar, he didn't return Anakin’s lightsaber. He took it because Anakin had abandoned his commitment to trust the Force in favor of power and destruction. The Chosen One had chosen a new life and was no longer worthy to wield the weapon of a Jedi, so Obi-Wan was obliged to take it from him.