Second Peter 1:5–7 is one of the few places in Scripture that uses the term brotherly kindness, although many more passages discuss the idea: “Now for this very reason also, applying all diligence, in your faith supply moral excellence, and in your moral excellence, knowledge, and in your knowledge, self-control, and in your self-control, perseverance, and in your perseverance, godliness, and in your godliness, brotherly kindness, and in your brotherly kindness, love” (NASB). These character qualities can be considered steps of spiritual growth. Peter continues by telling us why these character traits, including brotherly kindness, are so important: “For if these qualities are yours and are increasing, they render you neither useless nor unfruitful in the true knowledge of our Lord Jesus Christ” (verse 8).
What the NASB translates as “brotherly kindness” other translations call “mutual affection” (NIV) or simply “concern for others” (CEV). Everyone adopted into the family of God through faith in Jesus is called a “brother” or “sister” in Christ, and we are to relate to each other as spiritual siblings. Romans 12:10 tells us what brotherly kindness should look like: “Be devoted to one another in brotherly love. Outdo yourselves in honoring one another” (ESV).
Brotherly kindness is a major theme of the New Testament. Jesus said, “A new commandment I give to you, that you love one another: just as I have loved you, you also are to love one another” (John 13:34). In a healthy family, brothers and sisters love one another and look out for each other. If one family member is in trouble, the whole family rallies around to help. The old adage “He ain’t heavy; he’s my brother” captures God’s ideal for His children. We are to be kind to each other the way brothers and sisters in a loving family are.
The Bible gives examples of people practicing brotherly kindness. After David ascended to the throne of Israel, he asked, “Is there anyone still left of the house of Saul to whom I can show kindness for Jonathan’s sake?” (2 Samuel 9:1). He had no relationship with Saul’s extended family, yet, because of his close friendship with Saul’s son Jonathan, he wanted to show brotherly kindness to Jonathan’s family. Mephibosheth became the recipient of David’s kindness.
When the church at Antioch heard that the church in Jerusalem would soon be suffering from a famine, they gave sacrificially to help relieve their brothers’ and sisters’ financial burden (Acts 11:27–30). Churches in Macedonia and Achaia also contributed to the poor in Jerusalem. These were acts of brotherly kindness.
Brotherly kindness is the product of obeying the command of Philippians 2:3–4: “Do nothing out of selfish ambition or vain conceit. Rather, in humility value others above yourselves, not looking to your own interests but each of you to the interests of the others.” When we live every moment with the expectation of being a blessing to our brothers and sisters in Christ, we are fulfilling God’s desire for His church (Galatians 6:2).