Book 8 refuses to treat direct dominion as abstract spirituality. It says direct dominion begins when the vertical love of God and the horizontal love of a mature man and woman meet in a family centered on Him.
That is why marriage matters so much in the chapter. Direct dominion is not an inward state available to the isolated self. It is the point where heaven and earth become joined through a true couple and their household.
This also sharpens what the Kingdom of Heaven means. Heaven is not only where evil has been excluded. It is where God’s vertical heart and human horizontal love finally form one living order.
The practical implication is severe and beautiful: the family is not downstream from salvation. It is one of the primary places where salvation becomes concrete.