9 But concerning brotherly love you have no need that I should write to you, for you yourselves are taught by God to love one another; 10 and indeed you do so toward all the brethren who are in all Macedonia. But we urge you, brethren, that you increase more and more; (1 Thessalonians 4:9–10, NKJV)
The apostle uses two words for love in this passage; philadelphia (brotherly love) and agape (love). We are to have both warm affection and the abiding welfare of our brethren in our hearts and in our lives. There is always room for improving our brotherly love. God teaches us to love one another, and so we must earnestly strive not to take each other for granted. Brotherly love holds its brethren in high regard and responds with kind consideration toward them. Such love is not confined to our own circle of saints, for instance, just the local church to which we belong. The Thessalonian Christians’ love included the saints in the surrounding area. Furthermore, there is no limit to love. While Paul commended them for loving their brethren, he urged them to increase their love abundantly. The warm affection of brotherly love (philadelphia) must be coupled with the love (agape) that selflessly attends to others before itself. Agape is an exercise of the will, and so are commanded to “love (agapao) the brotherhood” (1 Peter 2:17). Let us strive to mature in love (agape) and in the warm affection of brotherly love (philadelphia).
7 For none of us lives to himself, and no one dies to himself. 8 For if we live, we live to the Lord; and if we die, we die to the Lord. Therefore, whether we live or die, we are the Lord’s. (Romans 14:7–8, NKJV)
Your life affects many others, and they also affect you. To borrow from the 17th-century English poet, John Donne, “No man is an island, entire of itself; every man is a piece of the continent, a part of the main. If a clod be washed away by the sea, Europe is the less…Any man’s death diminishes me, because I am involved in mankind, and therefore never send to know for whom the bell tolls; It tolls for thee.” Even more than being members of the human family, Christians are “members of one body” (the church). Our lives impact each other. Therefore, our choices must honor God as well as bless others. God does not teach us to isolate ourselves. Indeed, the very essence of brotherly love is outward-looking “for the interests of others” (Phil. 2:4). In the body of Christ, when one suffers, we all suffer; when one is honored, we all rejoice (1 Cor. 12:26). No one is an island.
Be kindly affectionate to one another with brotherly love, in honor giving preference to one another; (Romans 12:10, NKJV)
The regard and treatment of Christians toward one another is discussed here under the figure of a family. Brotherly love is to be marked by warm, familial affection. That is, we are to hold each other close like members of our family. Instead of clannishly separating from other Christians, we are to express warm affection for each other that grows out of family togetherness and familiarity. So, instead of jealously seeking honor for oneself above others, consider the needs and circumstances of other Christians first. We are a spiritual family, and that is what family does.