In his article, “The Wisdom of Kabbalah and Philosophy,” Baal HaSulam writes that love consists of four parts, meaning that when one starts to feel that he is receiving “something,” one can divide this “something” into four levels.
Kabbalists call the pleasant sensation that comes to us under the influence of the upper Light a gift. When we receive a present, we start searching for who gave it to us; we explore what this quality is that is the reason He treats us like this, with what intention and so on. In other words, we don’t get anything but the gift, but we can learn about the Giver by examining His gift and the impact that it produces on us.
If we were presented with a little box as a gift, we are unable to determine much by only looking at it, but we would obviously think that the one who sent it to us treats us well.
On the other hand, if the gift penetrates into us and produces a certain action in us, then we can figure out what the Giver expects from us and why He modifies our internal states the way He does.
We know our prior states and we feel our current, altered state, and the difference between them in certain properties and aspects. Then, we can realize what He wants of us. From the differences between the past and the present, we can tell who He is. In accordance with the changes as they change, we feel His positive qualities. He always changes us for the better, to the positive, to more. It makes us grow, and we start to realize that that is His qualities and that He wants to raise us up to Him.
Accordingly, we are able to distinguish between the four levels of attainment and the four worlds.
From the Fundamentals of Kabbalah 12/2/12