Albert Barnes Commentary 1 John 4:19

"We love, because he first loved us." — 1 John 4:19 (ASV)

We love him, because he first loved us. This passage can be understood in two ways:

1. That the fact that he first loved us is the ground or reason why we love him.
2. That, as a matter of fact, we have been brought to love him as a result of the love which he has manifested towards us, though the real ground of our love may be the excellence of his own character.

If the first explanation is the meaning, and if that were the only ground of love, then it would be mere selfishness ; and it cannot be believed that John meant to teach that this is the only reason for our love to God.

It is true, indeed, that this is a proper ground of love, or that we are bound to love God in proportion to the benefits we have received from his hand; but still, genuine love to God is something that cannot be explained by the mere fact that we have received favors from him.

The true, original ground of love to God is the excellence of his own character, apart from the question of whether we are to benefit or not. There is that in the Divine nature which a holy being will love, apart from the benefits he is to receive, and from any thought even of his own destiny.

It seems to me, therefore, that John must have meant here, in accordance with the second interpretation suggested above, that the fact that we love God is to be traced to the means he has used to bring us to himself, but without saying that this is the sole or even the main reason why we love him.

It was his love manifested to us by sending his Son to redeem us that will explain the fact that we now love him; but still, the real ground or reason why we love him is the infinite excellence of his own character.

It should be added here that many suppose that the Greek words rendered "we love" (hmeiv agapwmen) are not in the indicative mood but in the subjunctive mood, and that this is an exhortation: Let us love him, because he first loved us. So the Syriac, the Arabic, and the Vulgate read it; and so it is understood by Benson, Grotius, and Bloomfield.

The main idea would not be essentially different; and it is a proper ground of exhortation to love God because he has loved us, though the highest ground is because his character is infinitely worthy of love.