Incidentally, in the past days I have pondered relating questions. The subject is: "Unconditional love". First of all: I would define true (not sex etc. related love) to be: To have/live/be/manifest the will that the target person (or e.g. the whole of mankind) is/exists/lives/ is well.
I have come to the conclusion that if such an act of love is done for any personal gain, it is still of course valuable, but it is of less value. The word "conditional" in "unconditional love", to me, now does refer to this. Again: "Unconditional" would of course still mean "no matter what the other person does or if the person deserves it at all", but on this new higher level of looking at it, it would mean: "You don't do it for the pay", so to speak. A reward, or even negative repercussions, are not a condition that lets you stray from the path.
This is the answer that I would have for the big question of evil. We can come up with all kinds of concepts for doing good, concepts which work and stick, but in the end, there are many big/small/microscopic decisions where the cause&effect system that reality is does not play police, where you get away with it. And in those cases, the only concept I can think of is this: Decide for good because it's right. Maybe it'll make you feel better, and you can live better with yourself, but that ultimately is *still* personal gain. It's only pure love if you do it for the purpose of it being right.
Theists might say that they need God for such a morality. But I rather say that this higher source of value is not a person but instead "the truth". Does it pay? Maybe. No. Whatever. But I feel that it is right to do it - for the truth.