This is a special kind of copyright, known as a Creative Commons "share alike" copyright. Click on the graphic below for more details.
If this book fits your needs as a Unity teacher, then I want you to feel free to give away copies of this book to your students, in either printed or electronic form.
But if this book doesn't fit your needs, then I want you to feel free to improve upon it. I know this book isn't perfect. If you can make it better, then you are encouraged to adapt, edit and extend this material into your own book so that the Unity movement has the best possible course guide for Background of New Thought. To do that, all you need to do is (1) credit TruthUnity for the material that you use and (2) freely share your new work with others using this same Creative Commons "share alike" copyright.
Ok, you may ask, if I am "giving this away" then why have those two restrictions? That is the condition that has given us so much free software and other wonderful things in our digital age. What it means for this work is that if you and others improve on the material I've got here then I can incorporate your improvements back into my work, as long as I credit you for the material I use from your improvements. See how collaboration works today? That lets everyone else build on your work as well. Together, we will make a beautiful work.