People talk about love as if it is a thing in itself, but even when you break it down to neurotransmitters and brain activity, it isn't its own thing. It is the manifestation of multiple emotions, feelings of trust and dependency, responsibility, loyalty, protectiveness. It's happiness, frustration, hurt, ecstasy, attraction. You can't gussy it up into a bromide or a bible verse, or you're left with something inauthentic. Love is the good and the bad of a relationship, a complex mix of emotions in varying quantities for each distinct batch. It is the good and the bad, the said and unsaid, done and undone. When you try to quantify it as a thing in itself, it breaks down. There is no 'love' as its own entity, it is built of more fundamental parts.