Free will is the effect of the alchemical marriage, and we gain more free will as we approach it. Just as the alchemical marriage is a process we work towards, we work towards free will in our process. Our current free will is in our choice to process our way to the alchemical marriage. This lines up with the mystical text the “Kybalion”, which states:
The majority of people are more or less the slaves of heredity, environment, etc., and manifest very little Freedom. They are swayed by the opinions, customs and thoughts of the outside world, and also by their emotions, feelings, moods, etc. They manifest no Mastery, worthy of the name. They indignantly repudiate this assertion, saying, “Why, I certainly am free to act and do as I please–I do just what I want to do,” but they fail to explain whence arise the “want to” and “as I please.” What makes them “want to” do one thing in preference to another; what makes them “please” to do this, and not do that? Is there no “because” to their “pleasing” and “Wanting”? The Master can change these “pleases” and “wants” into others at the opposite end of the mental pole. He is able to “Will to will,” instead of to will because some feeling, mood, emotion, or environmental suggestion arouses a tendency or desire within him so to do. ~Chapter 12, Causality, The Kybalion