372. 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.