My Answer: How can you possibly check what level your teacher is and whether he is a Kabbalist or not? Who are you to examine this? What tools do you have and what tests can you perform?
Maybe you would test how well he knows theory and the Talmud Eser Sefirot? But everybody remembers Baal HaSulam’s story about the “kabbalists” whom he met in Jerusalem. They knew all the ARI’s books and the entire Book of Zohar by heart. If they heard the beginning of a sentence they could continue it to the end of a chapter.
Yet does it prove that they were Kabbalists and had attained spirituality? They were just a computer with good memory. Beside theoretical knowledge and the ability to present it skillfully, there seems to be no other criteria to be certain. How can you test this if you don’t have the appropriate tools?
Spirituality exists in the properties that you don’t possess yet and this makes you incapable of determining whether other people do have those spiritual properties or not. Besides, any Kabbalist can conceal himself as well. Even to another Kabbalist, another can “camouflage” himself to the extent that the other won’t recognize or sense anything.
That is why the only way to check someone is with one’s own heart. You should open your heart to yourself, never deceive yourself, and then see whether you are ready to follow this person without regret or self-coercion, and without fighting your doubts.
There might be some things that you don’t agree with, but you proceed anyway in order to give them a chance. You might not like his way of teaching or his behavior, but you are ready to check the principles he uses and why.
You are the one who has to investigate; no one else can do it instead of you. Who else can you trust? There is no difference between believing your teacher and trusting a person who tells you things about him. Whose word can you rely on? “To rely on someone” means to use “faith above reason" and trust that your teacher is in spirituality and knows what he is talking about.
That’s why only your heart can give you a hint. As it is said, “One should always learn where one’s heart desires.” It’s necessary to figure out exactly what your heart wants and then avoid other people’s opinions so that you can rely on your choice.
From the 4th part of the Daily Kabbalah Lesson 6/13/10, Article, “Make Yourself a Rav and Buy Yourself a Friend – 2”
Laitman.com Post: You Are The Only One Who Can Find The Truth
Laitman.com Post: Kabbalah Is A Science Where You Verify Things For Yourself
A Guide to the Hidden Wisdom of Kabbalah: "Finding the Right Teacher"
ARIfilms: "Spiritual Teacher – Kabbalah"