Love is a consequence of giving.  When a person gives, it is as if he is giving part of himself.  He therefore loves the recipient because he finds in him something of himself.  If his giving assumes great proportions and he lavishes loving-kindness on his neighbor with abundance, he will find himself included entirely in the other.  Then he can love his neighbor as himself – completely as himself – without any distinction. ~ R’ Eliyahu Dessler zt”l

R’ Dessler goes on to explain that this is why parents love their children so much – because they give so much to them.  He further explains that this is the recipe for a good marriage. Each spouse should focus on giving to the other because the more one gives, the more one loves.