We should be honest enough to say that we are learning love as we go . It is everything. Take it from one of the great atheists of all time, Bertrand Russell. He observed that despite all the complexities of the world's problems, our most urgent need is not for a new invention, or technique, but for something simple. Somebody with no brief for the Gospel, or the theological establishment, made the same simple and profound observation that Jesus made in another time and other context.
Love undergirds everything.
The amazing thing about the love that Jesus taught is that it isn't based on the obvious things that go for love, either in that society or in ours. People are programmed biologically to have a sexual response to other people. If you try to generalize about love based on that biological response, you will get only a very partial and skewed understanding of what love is. Or, as some discover, you will end up starved for love because that response doesn't always happen, or isn't returned as perfectly as you think you have given it. Marriages crumble and end because people think that if they can't maintain the spark that attracted them in the first place, there is nothing there.