So I'm going to stop calling this thing "love" and call it by it's Greek name "agape". Not because it makes me feel all fancy to be using Greek words, but because it's so important to make a distinction between the love that is God (agape), and the pale human shadow of that Great Love.
So, God is agape. In other words, to fully know agape, we have to fully know God... which we won't in this lifetime, but let's see if we can get a little glimpse of what agape truly means.
In I Corinthians 13 of the Bible there's a whole chapter about love. Early in the chapter it says something really interesting. It goes something like this:
"Even if I give away all my stuff and am willing to be burned to death, if I don't have agape, I'm nothing."
Wow, right. So being really generous or being willing to die for other people isn't (of and by itself) agape.
That means (among other things) that if we sacrifice our comfort and well-being for others, it isn't really love unless it's for their greater good. Too often, we try to please our loved ones (especially children) now - because we want to see them "happy" (and that makes us "happy") - at the expense of their future. It might make my kids "happy" to eat lollies every day of their lives, but, considering the cost to their future health, it's certainly not agape. Agape wants what is best for people, not what will make them feel good (of course, sometimes what makes people feel good is what's best for them, but we can't assume that making people feel good is agape all by itself).
So sacrifice and generosity aren't agape all by themselves. And that is just barely the beginning... More another time.