Growing up, Don Carson was probably the scholar I respected most. At university, he was respected to the point of being seen as almost inerrant.
Since then, I've increasingly come to see that while he is a very good scholar, and that books he writes are generally among the best on a topic, he is certainly fallible. In Carson's case, that means that he sometimes has a tendency to assume his conclusions, and cover it up with weak arguments which he treats as strong. It's a common failing among well-regarded academics, on all sides of most debates. Don't get me wrong – most of his arguments are good, but it's taken me years to be able to see the difference between a good argument of his, an overstated argument with a right conclusion (according to fallible me) and an overstated argument with a wrong conclusion (according to fallible me).
The other common academic failing is that of overstating uncertainty, and that is more annoying because it allows almost any opinion to be treated as equally valid.
Anyway, this is an interesting book of Carson's. I bought it because I thought it would be about how to love people I find it difficult to love. It isn't really. It's more about what love means in situations when it is intellectually difficult to see, such as forgiving unrepentant enemies, how to love Osama Bin Laden, nature of just war, and so on. Much of it I agreed with, the rest of it was at least thought provoking.
There are also bits about the importance of love for God and other Christians, but Carson is at his best when he is doing exposition and intellectual analysis of situations rather than application.
Here's a great quote:
Popular culture saunters between a sentimental view and an erotic view of love. The erotic view is fed by television, movies, and certain popular books and articles; the sentimental view is nurtured by many streams, some of which we shall think about as we press on, but the result is a form of reductionism whose hold on the culture is outstripped only by its absurdity.
Applied to God, the sentimental view generates a deity with all the awesome holiness of a cuddly toy, all the moral integrity of a marshmallow... Applied to Christians, the sentimental view breeds expectations of transcendental niceness. Whatever else Christians should be, they should not be nice, where niceness means smiling a lot and never ever hinting that that anyone may be wrong about anything (because that isn't nice). In the local church it means abandoning church discipline (it isn't nice)...
None of this is to say that “un-niceness” has any allure for thoughtful Christians. It is merely to say that the surrounding culture's sophomoric reduction of “love”, even Christian love, into niceness does not give us the scope to think through the diversities of ways in which the Bible speaks of Christian love, the diversities of contexts that demand something a good deal more profound than sentimental niceness.