Theologian Natalia Marandiuc has claimed that “an inherent component of any compelling vision of the good needed for human well-being is the experience of belonging, or being attached through love” (24). Her argument draws on Søren Kierkegaard’s declaration
that “[l]ove is the source of everything” and that it builds people up. In fact, “to build up is exclusively characteristic of love.” But what does it mean to build up? For Kierkegaard, [...] it refers to the other person’s journey of becoming. The receiver of love is the one who is being built up, developing and growing into a fuller subjectivity by the very experience of being loved, even as the giver also becomes a more capacious person by and through loving. (132)
The belief that love is good, and therefore improves those who experience it, is widespread. Author Elizabeth Lowell has claimed that romance readers seek out romances to have “their belief in love’s constructive power affirmed” (91) because, out of all the genres, in romance alone is romantic love “affirmed as an immensely powerful constructive force in human life” (90). Another romance author, Melissa Storm, has written that “I'm a true believer in how love can come along at the perfect time and change our lives for the better–after all, it happened for me” and many romance novels can be read as illustrations that this belief is correct. True love, romance novels teach, brings happiness and improves lives: "Love doesn't destroy" (Biggs 78).
In many romances the characterisation is such that the protagonists complement each other, so that each brings out the best in the other, and they support each other to be the best they can be. Since individuals vary, the positive, personality-enhancing effects of love will also vary, and therefore so too will the metaphors used to indicate recognition of the ways in which love improves people. As one of the heroes of Heather Long's Wolves of Willow Bend series explains: “Mating is different for everyone. For some, it completes them. For others, it enhances who they are. For others, it opens a door to who they've always been.” His own mate tells him that “You make me whole [...] Like the piece I was always missing, but didn't realize wasn't there” and he responds that “You open doors in me. The world isn't a simple place, not really, but with you ... I can handle anything, I know it.” None of these metaphors involve a wholesale rejection of the person as they were. As one heroine reports, over the course of the process, “I haven’t changed. I don’t think I ever will. But I’ve grown. I’m growing” (Hibbert 2018). Thus while it may be "against romance novel law or something to pin your hopes on someone changing into the right person" (Tenino 199), it is quite commonplace to witness a protagonist “transforming into what he’s meant to be. Like a butterfly” (199) and receiving support to do so. In a relationship of mutual love, a secondary character in another novel declares, "You make each other better. If that isn't love, I don't know what is" (Nash).
At its simplest, this can be about increasing self-belief, as in Rebecca Taylor’s Affective Needs (2016), in which the hero tells the heroine that
"[...] Everything ... that's what I owe you."
I gave him my look of disbelief. "What? That's not true. Everything you've done you've done on your own."
"But I never would have believed I could, if I hadn't seen that belief through your eyes first. When you said I could make my life better ... that was it. That was the moment I knew it too."
"You just never saw yourself the way I did."
"You're right. I never did."
The dynamics of personal improvement described here are very similar to those in a romance published over 100 years earlier: Attraction (1913) by Louise Mack, in which the hero at the end offers up a toast “To Her whose belief in me made all things possible" (336). Knowing that they are loved can give people the necessary self-belief to improve.
One final point which should be mentioned is that love's benefits are often shown to flow outwards from the central relationship. This aspect of love is implicit in Pamela Regis's description of an "accidental element" (38) in romance whereby a society which is "flawed" (31) is "reconstituted" (38). Romance reader Jennifer Porter has argued that, far from being an optional element, for many readers it is as necessary as the happy ending for the protagonists: "We romance readers don’t just want the HEA/FN [Happy Ever After/For Now] we want an HEA/FN in a righted universe. If the universe isn’t right, many of use [sic] reject the HEA/FN even if it exists." The extent to which a society or "universe" is, or can be, "reconstituted" and "righted" will vary from novel to novel, but it is likely that love will be powerfully good enough to produce at least some net benefit for the protagonists' community. As a ghost says in Kaje Harper's Nor Iron Bars a Cage (2013), “Each moment of love in the world lifts us all up. Any kind of love.”