In 1 John 3-4, it is made clear that only those who have personally experienced and continue to learn about the transforming love of God through the saving work of Jesus Christ, will love as God desires for them to love, since only then will we have the correct standard of love and the correct motive for love. Loving others BEGINS WITH knowing the love of God. And knowing the love of God begins with knowing the cross. And really knowing the cross begins with knowing our wickedness. There is no understanding of love apart from those things. This is the love we have come to know in that we look at the sacrifice on the cross where Jesus Christ, God the Son, the sinless one, the one who had the highest position and privilege in Heaven, laid down his life for sinful humans. Christ has defined love and thus love at its very essence requires sacrifice. That’s why Christians must not, should not and cannot think about the love of God apart from the cross of Christ.
Before being made alive in Christ, we did not understand love. Sure we might have adopted a superficial, worldly definition of love that basically says, “Be nice to others when you feel like it or when you will get something in return, whether the reward was tangible or intangible.” But upon hearing the gospel and entrusting yourself to it, you came to know real love and hopefully you haven’t stopped enlarging your view of that love as time goes on. So in the death of Christ we have the supreme picture of love; we have the ultimate prototype of love; and we have the premier example of love in the history of the world. And notice what John highlights in this verse about the crucifixion of Christ—not the atonement, not propitiation, not reconciliation. At this particular point in the epistle, John is not concerned with the results of cross for the believer, but the act of Christ giving himself up for others. As we will see next in the second half of the verse, this is the principle that is to be emulated in the body of Christ.
Here’s the flow of thought of v.16: Since Christ has loved you like this, you ought to love your brothers and sisters in the same way. That doesn’t mean we have to find a way to be physically crucified, for that would benefit no one. What it means to lay down our lives most often is a sacrifice of our time, interests, resources, desires or comfort in order to serve someone else. To put it in simple terms; in order to love as Christ loved us, we must choose to love someone else instead of ourselves. What a privilege to display Christ in this way!