Oneness
Before the Creator had created any form, there was only the Creator. Thus, a Creator cannot create anything that is separated from itself; it must create everything out of its own being. It does this by manifesting its being as the Ma-ter light and thus taking on whatever form is projected upon it by self-aware beings with free will. Thus, beneath any form, any appearance, there is still the oneness of the Creator. Separation from God is always an illusion, and it is this final illusion we must overcome before we can ascend.
Path
The masters teach that the ultimate goal of life on earth is to manifest the Christ consciousness, which allows us to permanently ascend to the spiritual realm and become ascended masters. Yet we are originally created at a much lower state of consciousness, and thus we follow a gradual path that raises our consciousness to the ultimate level. The masters say there are 144 different levels of consciousness that are possible for people on earth. You can ascend only after reaching the 144th level.
Physical body, physical mind
Obviously, this refers to the body. The physical mind is that part of the brain and nervous system that is designed to regulate the functions of the body, even prompting us to take care of the needs of the body. This is what gives us certain instinctual cravings for protection, food, sex and other physical needs.
There is nothing inherently wrong with taking care of the needs of the body, but the physical mind is not capable up limiting these needs. Thus, if we do not take command over the physical mind, all of our attention and energy can be spent on fulfilling the needs of the body, leaving nothing left over for spiritual growth.