I’m a Thelemite so I hold the Book of The Law in high regard, though the book itself stresses that everyone must interpret and apply it to their own life in their own manner. Two people can have two very different interpretations of it and both be “right”, because Thelema is centered around the individual it has as many manifestions as there are individual Thelemites.
From my own personal understanding of it, it is a divinely inspired work that uses symbolism and metaphor to describe the new shift in consciousness humanity is entering into, called the Aeon of Horus. The energies of the New Aeon are transitioning humanity into the next step of spiritual evolution where the old religious spiritual systems based around the archetype of the dying god Osiris are replaced with the mythos of the Crowned and Conquering child Horus. Thus no longer do humans need to be chained to the suffering and submission to a patriarchal deity but rather know the god in themselves through the understanding execution of their True Wills as individuals.
That’s just my best short summary I cane give of it as I understand it that I have time to type right now. It’s a very deep subject and there’s tons of mysteries in Liber Al that can be revealed to one.