Magic is the Art of producing change in conformity with the human will. In this way, we can see why the only Law in Thelema is "Do what thou wilt", as in order to follow nature's intention for us, we must continuously express our "will" with no doubt or fear whatsoever. If this is the only law or rule, what then are the "sins" according to Thelema? What is an indicator that we are falling into "wrong" behavior? The core scripture of Thelema outlining the code of conduct for the New Aeon we as human beings are being initiated into at large is very clear about this and the answer is: "the only sin, is restriction". What then is restriction? Restriction is a mental tendency or direct action that seeks to control and restrain human behavior or sexual expression from the natural flow and course of motion. The Law of Thelema is the Law of pure and total Liberty and to follow it, you must be quite content to let others do whatever they want and refuse to interfere. In this way, we can say that the New Aeon's code of conduct is ruled by Ketu (as a reaction to the overarching impurity and Rahu energies arising), in that, just like Ketu, we must be unattached and apathetic to the actions of others, as long as they do not interfere with your personal freedom or the personal freedom of others. This is an explicitly sexual doctrine, in that the majority of restrictions on human behavior and society at large revolve around controlling the libido in order maintain their position of power. The reason why anyone in power wants to pass rules and restrictions on human sexuality is that without using and directing your sexual energy and arousing yourself, there is absolutely no possibility to manifest your will in reality. By forcing people to stifle and repress their sexuality, they maintain their control over those who allow themselves to give up their sexual energy in service to their controllers. This is why in my female path course, I always explain that without being completely honest about your sexual desires and learning how to generate "energized enthusiasm", your Kundalini will lay dormant and asleep, and you will remain ignorant and unable to manifest your desires or achieve liberation. Notice I used the word "liberation", which is the opposite of "enslavement", which revolves around artificial control and restriction. If you restrict your sexual energy, you impede your life force and you will never be able to leave your physical body and astral travel, develop clairvoyance or clairaudience, or even perform divination correctly because all of these things require the loosening of your sexual energy, which allows you to access the trance state. This is because arousal is the mechanism behind how the Kundalini awakens due to the suspension of the ego and the rational mind that keeps it identifying with the physical body and enmeshed in the material world, totally deluded and unaware of the non-physical dimension. Any form of artificial restriction we place on ourselves is done through the mechanism of the mind and Rahu, which then impedes your spiritual abilities, or denies you from accessing the occult knowledge or power that you desire.
The reason why most people restrict their sexual energy in the first place revolves around shame and a real fear of their own true nature. They feel "shame" at the thought of pleasing or gratifying themselves, and this denial of your own true sexual nature is your innate fear and resistance towards Truth itself. To achieve self-realization you must learn to "know yourself", but this is not just an intellectual exercise, as you must also embody your true self and, by extension, exercise your unique sexual expression-- or, cut yourself off from your life-force itself and experience true spiritual death, and remain ignorant of your sexuality/true nature. This is why you will often hear Thelemites reciting "There is no shame, there is no guilt, the only Law is do what thou wilt" because actually doing your will and removing all of the artificial restrictions, false ideologies, and personal inhibitions to your own self takes real work and does not happen over night. You must constantly remind yourself that you are Free and that all restrictions are illusions, or you will most likely fall into "sin" and begin creating artificial restrictions for yourself and others. "No I cannot have this sexual experience, it is forbidden". "No, I cannot do this career what will my mother think?". "No, she must not dress that way, for men will become aroused and it is my self-appointed office to define what is acceptable sexual behavior for men.", "No people must not be allowed to smoke weed, because they must follow my ideas on how to live because I know better". All restrictive tendencies within yourself that you have to control or limit yourself and others in artificial ways must be eliminated if you want liberation. You can become your own Star and enjoy your own light, or choose to orbit and follow another, giving up the light of your own Star. To those who are truly wanting to be free, however, they will have no problem removing any eclipsing illusion or restriction thrown at them, until they are bathed in the everlasting light of truth and peace, that all who will settle for nothing less-- and all who are never willing to settle for the dark of restriction-- eventually get to view. This is why Marcelo Motta described true Thelemites (any practitioners of "will", Thelema meaning "will" in Greek, which can be found across cultures-- such as those who follow the code of Svecchācāra in India) as "children of the Sun", as they dwell in the light of truth and do not not fear their real and true sexual expression, or refuse to face or accept it, but bring it to the light fearlessly and shamelessly.