There are three parts to Kabbalah; Theoretical Kabbalah, Meditational Kabbalah and Practical Kabbalah (Kabbalah Masit)
Theoretical Kabbalah consists of studying the system of Kabbalah.
Just as one analyzes the logic of gemarah, so too one studies the wisdom of Kabbalah.
Theoretical Kabbalah deals with the structure of the spiritual worlds and the way they manifest in the physical domain.
Common texts dealing with Theoretical Kabbalah are Kitvi Ari, Ramchal, Pardes Rimionim, and the Zohar.
There is widespread misunderstanding regarding Kabbalah.
People fear studying Kabbalah will make them insane and cause them to die young, they think one must be forty years old, married, and finished learning Talmod study kabbalah.
This is ridicules, no one ever went insane from learning Theoretical Kabbalah.
There are different levels to Kabbalah, the advanced levels will not be understood until one has gained wisdom and is fluent in Talmud.
The hakdomos, basic instructions of Kabbalah must be known to everyone.
Without this information Judaism does not make sense.
How can one be expected to sacrifice for the religion when he does not even understand it.
When one learns Kabbalah he understands, and lives the Torah.
Meditational Kabbalah
When one meditates he can separate his soul from his body and transcend to the upper universes.
Theoretical Kabbalah serves as a map telling one how to prepare and where to go.
Although many religions practice meditation, they never leave the realm of the klipah since they have defiled themselves.
When one keeps the rules of halacha and practices the ways of Kabbalah, he purifies himself. If he then meditates, he can climb to the highest spiritual levels.
Meditation involves controlling ones thought process, blocking out the five senses and entering Mochin Dgadlus (expanded consciousness).
Unless one meditates he is only using three to five percent of his brain.
Part of the brain receives signals of spirituality. These signals are very sublime and are blocked out by the other five senses.
When one clears his head of all thought he can feel spirituality. If one keeps on working on this he can transcend to the upper worlds.
Meditation was the mainframe of Judiasim and was practiced by all Jews.
The highest level of meditation is prophecy.
There were over a million prophets. They attended schools called Beni Haniviem where they learned meditative techniques.
Maseh Merkavah consists of meditative techniques used to transcend to the spiritual worlds.
One of the main draws of Avodah Zarah (Idol Worship) was the meditative experience, if they could not get it from the side of holiness they would go to the other side.
Experiences during meditation are extremely enjoyable, they lead to extreme ecstasy . People would even go to the Sitra Achra to receive such an experience.
Drugs provide a very low copy of the meditative experience, yet they are constantly used by people, despite the destruction they cause.
Meditative experiences are so enjoyable that a person might not want to come back down, it is from this that people go insane.
If a person has a wife and children he is motivated to come back down. This is the reason why many advanced schools of meditation would not accept a person unless he was married and in full control of his desires.
Even after prophecy ended, meditation was still an important aspect of Judaism.
Hacholot Rabbati describes how R’Nechunya ben Haknah, R’Yishmoel and many other Tanoyim used the meditative methods of Maseh Merkavah to reach the high levels of Alom Yitzirah.
All Rishonim and many Achronim practiced meditation.
Since these topics involved the highest mysteries of the Torah, they were never written down. The few manuscripts that existed were never published.
If one knows the mysteries of Kabbalah he can see many hints and references in the Mishnah and the works of the Rishonim.
The main down play of meditation happened during the time of Shabti Tzvi.
Shabti Tzvi had many powers which he received from Meditative and Practical kabbalah.
R’ Yisroel Bal Shem and the Nistorim tried to bring these issues back out to the public.
The first generations of Chasidim were very busy with meditation and wrote extensively on this topic.
With the rise of the Enlightenment Movement in Europe meditation lost all its status.
Experiences that occur in a state of expanded consciousness are logically impossible to describe to someone who was never there.
Even the Chasidim and many Kabbalists lost their focus and started ignoring meditation.
It is known that prophecy must return before the coming of Moshiach. The only way to reach prophecy is through meditation.
In addition it is very hard to reach any high levels unless one practices meditation.
Every one must do R’ Nachman’s meditation, Hisbodedute- spontanous prayer.
Practical Kabbalah
Practical Kabbalah involves the coercing of angels and demons to change nature.
Practical Kabbalah overlaps with Meditative Kabbalah, many of these methods only work if done in a meditative state.
For example one might have to meditate on many things such as his breath and pronunciation on every letter of a divine name. This is impossible when not in expanded state of conscience.
The use of Practical Kabbalah was frowned upon by all leading Kabbalists.
Only one who had purified himself totally can use these methods and remain unharmed.
Many righteous people reached these levels and were known as Bali Shem (masters of the name).
When one forces an angel to do something, the angel wants to strike him down and kill him.
However after one dies he still has a share in the world to come. The angels make you sin until you lose this also, destroying the person totally.
One who uses practical kabbalah might get what he wants but it comes with a package.
Demons are like the mafia, once one starts dealing with them they will not leave him until he is destroyed from this world.
People should stay far away from Practical Kabbalah, whoever uses it will gain nothing but suffering.
http://truekabbalah.org/kabbalah/introduction_kabbalah.htm