As human beings, we have two capabilities that make up our life: motivation and understanding. These capabilities are distinct from each other, but they are created so that they form a single entity. Taken together, they are called the mind. These capabilities are the human mind, and that is where all our life force is.
Just as everything in the universe that is in harmony with the divine plan relates to goodness and truth, everything in a human being relates to motivation and understanding. The goodness in us is our motivation, and the truth in us is our understanding. These two capabilities, or life forces, are the reservoir and ground for the goodness and truth in us. Motivation is the reservoir and ground for all our good qualities, and understanding is the reservoir and ground for all our true ideas. The goodness and truth in us are nowhere else. This means the love and faith in us are nowhere else either, since love and goodness relate to each other, and faith and truth relate to each other.
So everything in the universe relates to goodness and truth, and everything in religion relates to the good qualities that come from love and the true ideas that are part of faith. Also, our two capabilities of motivation and understanding are what make us human. That is why an explanation of motivation and understanding is also included in this religious philosophy. Otherwise we would not have a clear idea about them, and there would not be a solid basis for our thinking.
Motivation and understanding also make up our spirit, since our wisdom, our understanding, and our life as a whole are contained in them. Our body simply does what it is told to do.
from The Heavenly City, Chapter 2