¹⁰By this the children of God and the children of the devil are obvious: anyone who does not practice righteousness is not of God, nor the one who does not love his brother. ¹¹For this is the message which you have heard from the beginning, that we should love one another; ¹²not as Cain, who was of the evil one and slew his brother. And for what reason did he slay him? Because his deeds were evil, and his brother’s were righteous.

The word “obvious” tells us that outward perceptions are the focus of John’s teaching here. “Practice” points to behavior as a way of life. The person who lives an outwardly sinful lifestyle, particularly the one who does not show love for fellow believers, gives no evidence of genuine faith. John might here put a footnote referring back to what he wrote in his gospel account of the life of Christ (but he expects his readers would know this). Jesus had explicitly taught this in the upper room to His closest followers just before His crucifixion: “By this all men will know that you are My disciples, if you have love for one another” (John 13:35). This truth was indelibly etched on John’s heart. The most significant evidence of true faith and obedience to Christ is our love for fellow Christians.

Of course, judging someone’s eternal destiny is God’s prerogative, not ours. We need to remember that when we judge others for their behaviors, we invite God to treat us in the same way. This teaching of Jesus (on which John is now reflecting) is not meant to provide us fodder to criticize the behavior of other Christians. No, it is given to us for our self-reflection. I must ask myself, “Am I demonstrating evidence of true faith in my love for fellow believers? What about those in the church I attend whose lifestyle I disapprove of? Do I love even them? Do I love that brother or sister who offended me? Am I unwilling to forgive someone?” These are not new questions but ones every Christian has heard from the beginning.

To bring the point home, John refers to one of the earliest stories in Scripture. The question has interested scholars and students of the Word alike: why did God accept Abel’s sacrifice and not Cain’s? The story does not indicate that God had asked them for a gift, much less an animal sacrifice (Gen. 4:2–8). Inspired by the Holy Spirit, John tells us that Cain was acting under the influence of “the evil one,” the devil. His willing complicity was apparent. How would we know from the story itself? Look how he treated his brother, in anger killing him. His actions showed the character of his heart. By analogy, John teaches us that our treatment of our brothers in Christ reveals the genuineness of our faith.

PRAYER: Lord, I ask Your forgiveness for the way I sometimes treat my fellow believers.