This is how we've come to understand and experience love:
Christ sacrificed his life for us.
If you see some brother or sister in need and have the means to do something about it but turn a cold shoulder and do nothing, what happens to God's love? It disappears. And you made it disappear.
What's the Point?
We've received God's Love for free and was shown to us in the most perfect way (laying down His life for us). God expects for us to show the same love to others as well!