The phrase “my brother’s keeper” occurs in the context of the story of Cain and Abel in Genesis 4:1-9. After the Lord God had expelled Adam and Eve from the Garden of Eden for their disobedience, Cain killed his brother Abel out of jealousy that God had found Abel’s sacrifice acceptable, but He had rejected Cain’s. After the murder, the Lord, knowing full well what had happened, asked Cain where Abel was. Cain’s response was "I do not know. Am I my brother’s keeper?"
There is a grain of truth in this brazen lie, despite the surly response Cain offers to the God who created him. While no one is the absolute “keeper” of others in that we are not responsible for everyone’s safety when we are not present, every man is his brother’s keeper in that we are not to commit violent acts against them or allow others to do so if we can prevent it. This sort of “keeping” is something God rightfully demands of everyone, on the grounds of both justice and love. But Cain’s reply indicates a total lack of any kind of feeling for another human being—not to mention the absence of brotherly love—and the overriding presence of the kind of selfishness which kills affection and gives rise to hatred.
So are Christians to be the keepers of other Christians? Yes, in two ways. First we are not to commit acts of violence against one another. This includes violence of the tongue in the form of gossip and “quarreling, jealousy, outbursts of anger, factions, slander, gossip, arrogance and disorder” (2 Corinthians 12:20). Second, we are to exhibit brotherly love toward our brothers and sisters in Christ with a tender heart and a humble mind (1 Peter 3:8). In this way, we “keep” those for whom Christ gave His life.
One of the golden chapters of the Bible is 1 Corinthians 13. In this magnificent portion of the Scriptures, we are reminded that love is even greater than faith and hope. Chapter 13 comes on the heels of Paul’s explanation of how the Body of Christ (the Church) is like the human body and is made up of many members, all of whom are important to the function and well-being of the Body. We are continually encouraged throughout the New Testament to love one another (Hebrews 13:1; Romans 12:10; 1 Thessalonians 4:9). Sometimes love must correct, admonish or reprove (2 Thessalonians 3:13-15; Matthew 18:15). However, correction is always to be done in the spirit of love with the goal of reconciliation.
Paul the apostle wrote to the church at Thessalonica, “And we urge you, brethren, to recognize those who labor among you, and are over you in the Lord and admonish you, and to esteem them very highly in love for their work’s sake. Be at peace among yourselves. Now we exhort you, brethren, warn those who are unruly, comfort the fainthearted, uphold the weak, be patient with all. See that no one renders evil for evil to anyone, but always pursue what is good both for yourselves and for all” (1 Thessalonians 5:12-15).
So, as Christians, we are to be our brother’s keeper. As Paul wrote, “Therefore let us pursue the things which make for peace and the things by which one may edify (build up) another” (Romans 14:19).