Yes, I believe I understood you correctly, however, contrary to your statement, in actuality good can exist without evil. The kingdom of heaven is not subject to this world's perception or logic. The kingdom of heaven existed without the presence of evil, as did man before the fall . Earthly concepts such as Yin Yang or a balance of positive and negative, right and wrong, good and evil, are not essential to Heaven's existence nor the existence of goodness.
We know that evil exists in this world in both the internal and external make up of this earthly existence, however, evil as we know it, will one day be removed from the earth.