You're asking an atheist such a silly question? I know that the emotion we humans call love actually exists. I know god doesn't. The two are mutually exclusive. You stop it! There is no way I would insist that loves requires God or that it is a proof of God.
When you insist that love requires your version of god, and that love is proof of your god, you are just making stuff up. Stop it.
All that I am saying is that you are fooling yourself if you think that love is real and that God is not.
What proof that love is real do you base your belief on? (beside you feeling it)
All it is is feelings. It is real to us humans. As is disgust and anger. That doesn't mean it is physically real like a an atom of iron, which itself isn't as real as real as we think, but it'll do in this case.
It doesn't have to be real to be important to people. Witness the World Cup. There is nothing actually important about a bunch of guys running around on a field chasing a ball, but many make it important, at at the point it becomes real to them.
Love is our attachment to people and things that makes us feel good. That is all it is. A feedback loop that we have labeled for our convenience.
God on the other hand, is a figment of the imagination that isn't actually important except to those who have decided it is. The concept is neither universal or consistent. Yes, many have gods, but not everyone has your god. Or your version of your god. Or the version of god you have this week that might vary a bit from the one you had last week.
So, love is real in that humans call it real. Since we don't therefore say we're gonna roast in hell if we don't have love, etc., it is pretty much benign. The hate your god generates, on the other hand, is very real (Crusades, anyone) and kind of hard on the population as a whole.
Yes, love can hurt too, when the non-real aspects of it get redefined to mean obsession=love or possession = love, where we end up with stalkers and wife beaters and such. But generally people in love don't fly into buildings or indulge in other attacks that kills thousands or tens of thousands. Love doesn't quite seem to be able to generate as much passion as religion, I guess.
On second thought, it may well be that love=god, because neither are actually real.