First, though, I need to say something about the balance. It is recognized that when two forces act against each other and when one reacts and resists as much as the other acts and pushes, neither has any force because each has the same amount of power. Then either can be moved by a third force at will, since when the two have no force because of their equal resistance, the force of the third has total control and acts as easily as if there were no resistance at all.
There is this kind of equilibrium between heaven and hell. However, it is not the kind of equilibrium that occurs between two people who are fighting physically, with one just as strong as the other; it is rather a spiritual balance, one of the false against the true and the evil against the good. Malicious falsity constantly breathes forth from hell and benevolent truth constantly breathes forth from heaven. This is the spiritual balance that provides us with our freedom for thinking and intending, since everything we think and intend depends either on evil and its consequent falsity or on good and its consequent truth.
So when we are in this state of equilibrium, we are in freedom either to let in and accept what is evil from hell and its consequent falsity or to let in and accept what is good from heaven and its consequent truth. Each of us is kept in this equilibrium by the Lord, who governs both heaven and hell.
I will explain later, in a separate chapter, why we are kept in this freedom by means of the balance, and why the evil and the false are not taken away from us by divine power and the good and true instilled.
from Heaven and Hell, Section 537