Answer: A person isn’t shown more than he can bear. If he were shown his real state, he would simply burn like in a short circuit. So we are constantly held between certain limits, between two points, so that a person will be able to bear it. It is like a fuse that burns when the current is too strong. As long as the current is normal, it transmits it. Its role is to hold on until a critical situation occurs and then it burns out, but it keeps the system intact.
Everything has a certain limit, and so from above, a person is gradually shown the AHP of the upper level, its posterior. If he is suitable for it as a result of his own exertion, then he is ready to ascend to the next level.
From the 1st part of the Daily Kabbalah Lesson 11/24/13, Writings of Rabash