The reason the divine nature that emanates from the Lord flows primarily into marriage love is that marriage love flows down from the union of the good and the true, for as already noted, it does not matter whether you talk about the union of intellect and volition or the union of the good and the true. The union of the good and the true finds its origin in the Lord’s divine love for everyone in the heavens and on earth. Divine good emanates from this divine love, and divine good is accepted by angels and by us in divine truths, truth being the only vessel for the good. So nothing from the Lord and heaven can be accepted by people who are not interested in truth. To the extent that true elements are united to what is good within us, then, we are united to the Lord and heaven. This is the actual source of marriage love, which means that it is the actual matrix for the inflow of the Divine.
This is why the union of the good and the true in the heavens is called the heavenly marriage and why heaven is compared to a marriage in the Word and is even called “a marriage.” It is why the Lord is called the Bridegroom and Husband, and heaven and the church are called the bride and wife.
When the good and the true are united in an angel or in one of us, they are not two entities but one, since the good then follows from the true and the true from the good. This union is like the one that occurs when we think what we intend and intend what we think. Then our thought and our intention form a unity; the thought forms or presents in a form what our volition intends, and our volition gives it its appeal. This is also why two spouses in heaven are not called two angels, but one.
Again, this is the meaning of the Lord’s words,
Have you not read that the One who made them from the beginning made them male and female and said, “For this reason a man shall leave his father and mother and cling to his wife, and the two will become one flesh.” So they are no longer two, but are one flesh. What God has united, let no one sever. Not everyone accepts this word, only those to whom it is given. (Matthew 19:4–6, 11; Mark 10:6–9; Genesis 2:24)
Here we have a description of the heavenly marriage angels are in and at the same time the marriage of the good and the true. “Let no one sever what God has united” means that the good is not to be severed from the true.
We can now see from the foregoing where true marriage love comes from, namely that it first takes form in the minds of the individuals in the marriage and then comes down and flows into their bodies, where it is perceived and felt as love. Actually, everything that is perceived and felt in the body finds its origin in its spiritual counterpart because it comes from our intellect and volition. Intellect and volition make up our spiritual person. Everything that comes down into the body from our spiritual person comes to view there in some other guise; but there is still a similarity and agreement like that between the soul and the body, like a cause and its effect, as can be gathered from what was presented in the two chapters on correspondences.
from Heaven and Hell, Sections 371-373