A number of other books has been written about these seven principles, using somewhat more modern language, but this book is the classic. This is not just a theory or a philosophy - the principles, being universal, are down-to-earth practical. If you apply them consciously in your life, your life will change.
While in times long gone by, these may have seemed to be only arbitrary spiritual principles, they are in accord with the view of quantum physics. Kybalion states that universe is mind-like in nature; quantum physics states that the universe is composed out of intelligent energy. The rest of the book describes how to manifest anything with one's thoughts - the process of manifestation, and it reminds me of the book "Dimensional Structure of Consciousness" by Samuel Avery.
The most important part of this book - other than pointing out these principles is that they are UNIVERSAL - they allways work, they express throughout nature and if you use them and apply the consciously, you can create whatever you can possibly desire in your life. You will know then that there is a law and that it works with mathematical precision, and that you can ALWAYS count on it.
The moment you grasp this truth, you will never ever again wish or hope for something to happen, you will know that you have the power to create it and you will be certain of it. And when you use this principles consciously and experience the truth of them - no one in the entire world will ever be able to talk you out of fulfilling your heart's desires. Even if the entire world doubts and laughs at you, you will not care because you'll KNOW that you CAN. You will have the "key".