In verse 16, John teaches that we can know love by observing the way Jesus lived His life. He sacrificed His life for us by laying it down each day, as well as in death, setting us an example to follow in our relations with the brethren. In verse 17, he provides a practical illustration of a way we can lay down our life in love. Then, in verse 18, he encourages us not merely to agree with truth but to take action to meet a brother's need.
Verse 19 begins to show the effect of devoted sacrifice to this way of life. The persuasive power of knowing we are doing the right things inspires assurance, confidence, and satisfaction; we feel a positive sense that we are right with God. He then explains that, when these are not produced—but instead we feel guilt and condemnation because we know we are not doing well, and our concern for not being perfect overwhelms us—we need to go to God for forgiveness because He will forgive.
Verse 21 is a subtle encouragement to repent, to turn from our self-centeredness so we can be at peace with God and within ourselves. Verse 22 discloses the positive effect of laying down our lives in sacrifice for our brethren by devotedly keeping the commandments: answered prayers. Living by faith and displaying it through a life of sacrificial love is the theme of verse 23, and finally, in verse 24, he reveals another positive effect: to know absolutely that He lives in us and we in Him. Our lives revolve around faith in this knowledge.
John W. Ritenbaugh
The Offerings of Leviticus (Part Four): The Peace Offering