Conditional love is attached to one particular person to the exclusion of others.  This is the beginning stage of love.  It may include positive feelings of deep, tender regard, of passion, affection, and solitude, arising from kinship or from devotion, desire, attraction, fondness, or warm personal attachment, which can fade over time. 

In marriage ceremonies, we promise to honor, love, and cherish till death do us part, but such promises are unrealistic.  Ask nearly any divorced couple.  Because conditional love is personal, attached to specific qualities, appearance, and other attributes of a particular person, when these qualities, appearance, or attributes change or fade, so can the love.

Until we move from conditional love, stores will be full of books and techniques to help struggling, suffering couples wondering whether or to not stay together because they don't feel fulfilled.

Unconditional love has no bounds, limits, strings, or conditions.  It loves without reason, whether or not it is loved or even appreciated in return.  It asks for nothing, but gives what it can.  It may be tough or tender, but it is always kind.  It values the lives of others as equal to—not less or more than—one's own.

And unconditional love extends to all souls, even while living with one chosen partner.  Loving everyone does not imply having sexual contact.  As most of us have intuitively learned, sexuality best serves our spiritual evolution within a single, committed relationship.  We can express nonexclusive love to friends, acquaintances, and other members of our human family without threatening the sanctity of our primary relationship, which remains the exclusive domain of sexual intimacy.

Parenthood serves as a primary theater and school of unconditional love.  Words we have all heard uttered with great solemnity at wedding ceremonies apply most universally to our love for our children, whom we love fiercely, with all our hearts—for better or for worse; for richer, for poorer; in sickness and in health… till death do us part.  Our children teach us how to love more than we could ever teach them.

If you can love even one other person with this fierce, sacrificial, unconditional generosity of spirit, then you can love many as you learn to cast your net of love wide enough to embrace all people as your children, as your brothers and your sisters.  This is no idealistic wish; this is a preview and prediction of your destiny.