If love of humanity is a virtue, and Christ was perfectly virtuous, then surely He must have "loved humanity" perfectly, "loved humanity" more than any one before or since. It is with a shock that we discover that He didn't "love humanity" at all. Perhaps GK Chesterton summed this up best,
Christ did not have the same kind of regard for one person as for another. We are specifically told that there were certain persons whom He especially loved. It is most improbable that He thought of other nations as He thought of His own. The sight of His national city moved Him to tears, and the highest compliment he paid was, ‘Behold an Israelite indeed....’ Christ commanded us to have love for all men, but even if we had equal love for all men, to speak of having the same love for all men is merely bewildering nonsense. If we love a man at all, the impression he produces on us must be vitally different to the impression produced by another man whom we love. To speak of having the same kind of regard for both is about as sensible as asking a man whether he prefers chrysanthemums or billiards. Christ did not love humanity; He never said He loved humanity; He loved men. Neither He nor anyone else can love humanity; it is like loving a gigantic centipede. (Varied Types)
Jesus, instead of commanding us to "love humanity" as many today would rather prattle on about, cut straight to the heart of the matter and called on us to not just love something abstract (that would be "loving a gigantic centipede"), but to love someone concrete - our neighbor (cf. Mk 12:31). Yes, your neighbor - that person who is delaying you in the express check out line with more than the allowed number of items, your neighbor - that person who just cut you off in traffic, your neighbor - your boss who just dressed you down in front of the rest of the staff, your neighbor - your wife who is nagging you today, even after a long day's work, your neighbor - your children who are giving you a hard time and disobeying, your neighbor - your parents or in-laws whose visits are so trying, that is who we are to love. There will be no "sliding by" with a general "love of humanity" for the follower of Christ, no! We must love even those closest to us, even those who irritate us the most. This struggle, to love a particular man, rather then men in general, is found on the lips of the atheist, Ivan Karamazov in Dostoevsky's classic The Brothers Karamazov,
"I could never understand how one can love one's neighbors. It's just one's neighbors, to my mind, that one can't love, though one might love those at a distance.... For anyone to love a man, he must be hidden, for as soon as he shows his face, love is gone."
How much easier it can be to love those far from us. Such a love is so undemanding. How many men, who won't say a word to their brother or father or mother, will gladly talk of the need to "free Tibet." How many men, even Christians, have former friends or literal neighbors they are feuding with, but will weep over the fate of people in Calcutta or East Africa? How many men hate another man in their own parish, while loving the poor in China? Of course, we are called to love those both near and far, we wouldn't want to only care about those near us, but how much easier is it to bemoan the children crossing the border while fuming at our own kids?
Chesterton himself recognized this interior struggle in the heart of men, how it can be easier to love the abstract concept of humanity than the all too concrete reality of an individual man, and even addressed its root cause,
“The Bible tells us to love our neighbors, and also to love our enemies; probably because they are generally the same people.”For it is only our neighbors, those who's lives intersect with our own day-in and day-out, that can cause us annoyance, grief, frustration, and pain. But it is precisely these who we are commanded to love. Which is precisely why we must never simply "love humanity," we must always love each individual man, woman, or child. For without this love, love of those we see in our lives, we cannot love God (cf. 1 Jn 4:20).