Herein is love - In this great gift is the highest expression of love, as if it had done all that it can do.
Not that we loved God - Not that we were in such a state that we might suppose he would make such a sacrifice for us, but just the opposite. If we had loved and obeyed him, we might have had reason to believe that he would be willing to show his love to us in a corresponding manner. But we were alienated from him. We had even no desire for his friendship and favor. In This state he showed the greatness of his love for us by giving his Son to die for his enemies. See the notes at Romans 5:7-8.
But that he loved us - Not that he approved our character, but that he desired our welfare. Hc loved us not with the love of complacency, but with the love of benevolence.
And sent his Son to be the propitiation for our sins - On the meaning of the word “propitiation,” see the notes at Romans 3:25. Compare the notes at 1 John 2:2.