There are three kinds of opponents of Kabbalah:
1. Those who say that there is no need for the concealed part of the Torah.
2. Those who say that Kabbalah is so great that it’s forbidden to study it.
3. Those who say that it’s a terrible thing to make a mistake in such exalted matters.
Rabbi Moshe Cordevero (the ‘Ramak’) “Da Et Elokey Avicha,” 118-132.
If a person from Israel lowers the importance of Kabbalah, he lowers the righteous of the nations of the world lower than the sinners, and thereby causes Israel to be scorned even to the point of annihilation. The entire fall of Israel happened because people have left Kabbalah.
Baal HaSulam. “Introduction to the Book of Zohar,” item 69.
Woe to the people who make the Light of the Messiah vanish from the world, so as never to return. They make the Torah dry, without the moist of mind and knowledge, for they confine themselves to the practical observance of commandments and do not wish to study the wisdom of Kabbalah. Alas, they cause by their deeds the poverty, the ruin and the robbery, the looting, the killings and destruction in the world.
Baal HaSulam. “Introduction to the Book of Zohar,” item 70.
Those who only study the Babylonian Talmud are like the blind gnawing at the wall.
Rav Chaim Vital. “Introduction to the Book Etz Haim,” part 1, 9-10.
The nations of the world say to Israel: “How is your Torah different from our teachings, since yours is also nothing but tales?” They will be punished for degrading the Torah this way. And their Torah causes exile and suffering in the world. But… our sages are pleased with what they have, and they assert that there is no other Torah but the simple Torah. Clearly there is no place for them in the world to come.
Rav Chaim Vital. “Introduction to the Book Etz Haim ,” part 1, 11-12.
Moses Maimonides (the Rambam): He who has not attained similarity to the Creator is not called a man, but is only an animal in the form of a human. However, he can do harm, which animals cannot, since the mind given to him to attain the Creator is used to harm others, and this makes him lower than an animal.
Rav Shim’on Lavi. “Katem Paz.”
This is an answer to all the “wise” people who oppose the study of Kabbalah: let those that study Kabbalah make mistakes and ask for the true path when they discover their mistakes. This is why their efforts are credited and rewarded by the Creator. And those who humiliate those who study Kabbalah will be condemned by the Creator.
Rav Shim’on Lavi. “Katem Paz.”
The wreath of the Torah is Kabbalah, which everyone rejects. But you, stretch out your hand and take it, since those who have never tried it, have never tasted the Light of the Torah and live in darkness. Great is the sin of those who use different excuses to avoid studying Kabbalah. And it is not the fault of the masses, but of their leaders, who neglect the study of Kabbalah and take pride in studying only the revealed Torah and in not needing anything but the simple understanding of the Torah.
Rabbi Pincus Eliyahu of Vilna Sefer HaBrit, part 2, article 12, chapter 5.
There are many ignorant people who refuse to study Kabbalah, but if they would listen to me, evil and misfortune would stop coming to our world, because man depends only on his efforts in studying Kabbalah.
Safrin, Yitzhak Yehudah Yehiel Notzer Hesed al Pirkei Avot, chapter 4, study 20.
Alas, these people, who make the Torah dry and do not wish to study the wisdom of Kabbalah; they cause by their deeds the poverty, the ruin and the robbery, the looting, the killings and destruction in the world.
Rabbi Shimon Bar Yochai (Rashbi) Tikunei Zohar, chapter 30.
Rashbi referred to those who study the simple Torah as “sleeping” because they don’t open their eyes to see the Creator’s love for them, as though they scorn it and do not know the path to perfection and adhesion with the Creator.
Rabbi Moshe ‘Haim Luzzatto (Ram’hal). “Shaarei Ramhal,” “Introduction to the Article Vikuah,” page 97.