EXPOSITION:
There is nothing comparable to the blessedness of living together as one. When brothers live together in peace and understanding, God pours His oil and dew on them. These grease their growth and water them for excellence.
It is said that two Christians are better than one if only they are one. Because God has commanded His blessings on brotherly love, any effort or adjustment you make to take away tension and dissension and to foster togetherness among brothers evokes His blessings on you.
As a child of God, you must be ready to suffer wrong for peace to prevail. Paul asks an intriguing question in this regard, “The very fact that you have legal disputes among yourselves shows that you have failed completely. Would it not be better for you to be wronged? Would it not be better for you to be robbed?” (1 Cor. 6:7).
You have to grow in maturity till your love for other believers is perfected (See 2 Peter 1:5-7). Jesus desires His followers to become one. He prayed for us in John 17, “Holy Father! Keep them safe by the power of your name, the name you gave me, so that they may be one just as you and I are one” and commanded us in John 15:12, “My commandment is this: love one another, just as I love you.”
As far as our Lord is concerned, those who love Him are those who obey His commands and so the one who loves his brother loves the Lord, simply put.