The reason we are controlled by the Lord through spirits is that we are not in the pattern of heaven. We are in fact born into evils that are from hell and are therefore exactly opposite to the divine pattern. This means that we need to be brought back into the pattern, and we cannot be brought back except through the agency of spirits. It would be different if we were born into the good that accords with heaven’s pattern. Then we would not be controlled by the Lord through the agency of spirits but through the pattern itself and therefore through a general inflow.
This [general] inflow determines the way things move from thought and intent into act and therefore determines our speech and actions, since these both do flow according to a natural pattern. So the spirits who are with us have nothing to do with these processes. Animals are also controlled through a general inflow from the spiritual world because they are in the pattern proper to their life, a pattern that they can neither distort nor destroy, because they do not have a rational faculty. (On the difference between humans and animals see above, Section 39.)
To continue with the general topic of the union of heaven with the human race, we need to be aware that the Lord flows into each one of us according to heaven’s design, into our inmost natures as well as into our outmost, and disposes us to accept heaven. He controls our outmost natures from the inmost and the inmost from the outmost at the same time, and in this way keeps everything about us in coherent connection. This inflow from the Lord is called a direct inflow, while a second inflow that happens through the agency of spirits is called an indirect inflow. The latter is sustained by the former. The direct inflow, an action of the Lord himself, is from his divine human. It comes into our intentions, and through our intentions into our understanding. This means it comes into what is good in us and through that good into what is true in us, or (which amounts to the same thing) into our love and through our love into our faith. It does not happen the other way around, much less into faith apart from love or into truth apart from good or into understanding apart from volition.
This divine inflow is unceasing and is accepted in what is good in good people, but not in evil ones. In them it is either rejected or stifled or distorted. So they have an evil life that spiritually understood is a death.
from Heaven and Hell, Sections 296, 297