In order to give the Kli freedom of choice, the Creator put two opposite forces in it: reception and bestowal. Creation is in the middle between them as the third line, as the fulcrum of a scale, and it decides which way to incline. That is how we are given the opportunity to be independent.
Question: What does it mean that creation “decides”? After all, when faced with a choice between good and evil, I will always choose good.
Answer: It depends on what you consider good. There are two scales: true versus false, and bitter versus sweet. Creation is being offered two ways of evaluating: good can be the receiving desire or the bestowing desire, and either can be felt as evil as well. The analysis can be made by the fulfillment in the receiving vessel or by the fulfillment in the bestowing vessel, in the left line or the right line.
You have two opportunities, each containing many traits. From these traits you begin to piece together the picture of your attitude. You thereby build yourself, putting together your spiritual Partzuf with all of its organs, tendons, flesh, bones, and so on. That is how many details you have to bring together into one whole.
From the 4th part of the Daily Kabbalah Lesson 1/6/11, “The Wisdom of Kabbalah and Philosophy”