John makes the powerful assertion that “we love Him because He first loved us” (1 John 4:19) in a section in which he is writing about how we should be expressing the love of God to others. He says a bit earlier in the letter that, “if God so loved us, we also ought to love one another” (1 John 4:11). John explains that we have come to know (experientially) and believe the agape love that God has for us (1 John 4:16), and because of that there is an expectation that we should act on that love. If love originates with God, then the one who is walking with God should be demonstrating love (1 John 4:17).
But what kind of love should we be expressing, and with what kind of love do “we love Him because He first loved us” (1 John 4:19)? His love is completed (or perfected) in us, in that we have confidence in the day of judgment. His love has kept us (by His grace through faith in Jesus Christ) from condemnation—that kind of life-saving love is what He has showed us and is what we are expected to show each other. That kind of love is free from fear, because there is no punishment in our futures (1 John 4:18). His love has given us great confidence, because He has removed our fear.
“We love Him because He first loved us” (1 John 4:19). Love made the first move; our love for God is simply a response to His love for us. We have the capacity to love, now understanding what love really is and how we can express that without fear because He first loved us—because He modeled for us what love looks like. As John said a bit earlier, we have come to know and believe His love (1 John 4:16), so we are neither ignorant nor incapable of showing His kind of love to others. In fact, loving our brother is not only an expectation; it is an imperative.
“We love Him because He first loved us (1 John 4:19), and because He first loved us, we can and must love others. If someone claims to love God whom we have not seen but doesn’t love his brother whom we have seen, then John says that person is lying (1 John 4:20). If we aren’t loving our brother, we aren’t loving God. John goes further, reminding his readers of Jesus’ commandment that we love our brother (1 John 4:21). John adds to the logic of love when he asserts that the believer in Jesus is born of God, and anyone who loves the Father should obviously love the child born of the Father (1 John 5:1). It would be nonsensical for a believer, then, not to love his brother in Christ. John explains it from a different angle as well: when we are loving God and observing His commandments, we can know we are loving the brethren (1 John 5:2).
To love God means to obey Him, especially considering that His commandments are not burdensome (1 John 5:3). John reminds us that our love should be a sincere love—like the love the Father has for us. We should not love simply with words, but with sincerity in our deeds (1 John 3:18). Loving in truth and sincerity is so important that John lists it as a logical next step after believing in Jesus—“This is His commandment, that we believe in the name of his Son Jesus Christ and love one another, just as He has commanded us (1 John 3:23, ESV). But God hasn’t simply told us to do something He wasn’t willing to do first, instead, “we love Him because He first loved us (1 John 4:19).