Why should there be a command to love?  Should it not be the most natural thing in the world to want friends?  To care for others, enjoy peace, and witness other's lives thrive within loving families and loving neighborhood is the stuff of nostalgia and idealism. 

In America we say people are entitled to the pursuit of happiness, and TV shows are made about whole communities turning out to build a house for some deserving family.  The whole crew and crowd claps to see them chosen to receive a big new house.  It's entertaining to see how keen everybody is to have these folks move from their former shack into an extravagantly appointed new house.

Why should there be a command to love if everyone approves the idea in principle? 

In fact, most people do support the notion that loving others is a good thing even if they don't do it.  Of those who trade on love Jesus acknowledged, "If you love those who love you, what credit is that to you?  Even 'sinners' love those who love them." (Luke 6:32)

The supreme command of Christ is not simply to love but to love as He has loved us.  Laying down of your life, delivery of all your valuables, making yourself accountable and vulnerable to another's every need: this just begins to get at what Jesus is commanding.

It has nothing to do with the lovability or gratitude of the recipients.  I doubt there would be an airing of "Extreme Home Makeover" if the benefited family on seeing their new house would scowl at the crowd, order the crew to get their "bleep-bleep" equipment and stinking bus away from my property, grab the keys, express no tears or thanks, and upon slamming the door complain the place isn't bigger.

Advertisers like Sears pay good money to sponsor sentimental love stories.  Town folk didn't kick in their volunteer time to have the new neighbors treat them like hog muck.  They expect some kind of return --- at the very least some warm, fuzzy feelings that we did a nice thing.

You don't have to command people to love like that.

To love as Christ loved us is quite another thing.  To love when there is absolutely no chance of any return is not the most natural thing in the world.  A desire to befriend those who exploit us is not instinctive to us.  No one makes abuse the theme of their nostalgia or gets homesick for obnoxious neighbors.  Yet, love for someone who doesn't have a clue what you're doing or care is the command of Christ.

Jesus is the only one fit to require such a thing because He's the only one who has shown such love.  To those who hurled insults at him, he did not retaliate.  Upon scoffers and blasphemers He sought benediction.  To those with a lifetime of crimes and misdemeanors He reached out with divine pardon.  The Bible says Jesus loved the rich young ruler who stacked up all his assets and affluence against Jesus and found Jesus wanting.  The guy chose his wealth and turned away.  Yet Jesus loved him.

To love as Jesus loves does not come by command.  The command to love is not to make you do it.  It is to show us that what we so often call love is nothing remotely like the real thing.  Examine what you call love for your wife and tear it to shreds.  You may call it love, but it is imperfect.  And you know that if you are honest. 

Consider what you call love of neighbor.  Wad it up and start from scratch.  It is entirely substandard.  Love of life; love of country; love of children; and love for the Lord are all on the blink.  None come from us by nature or by ruling.

Only that which is genuinely love deserves the name.  Such love is the substance of Christ. 

Love isn't a principle; it's a Person.  Love isn't a feeling; it's a Friend.  Love isn't created by command.  It comes by the Lord's unreserved choosing. 

Christ Jesus is the one who chose to love you and me, utterly unlovely and unlovable though we are.  Christ Jesus, while taking our contempt, still revealed to us the Father's heart.  Christ is the Person and the Friend who is love incarnate.  He has loved us from eternity, loves us now, and will love us for eternity.

Let us suppose no other source nor greater supply than Him.  "This is how we know what love is: Jesus Christ laid down his life for us." (1 Jn. 3:16a)  
 

So.  Why the command to love?

Christ's command is not to "come up" with it, but to spend it.