Shortly after Judas left to betray Jesus, our Lord told the apostles their brotherly love would be a defining characteristic. "A new commandment I give to you, that you love one another; as I have loved you, that you also love one another. By this all will know that you are My disciples, if you have love for one another." (John 14:34-35; NKJV)
Scripture is clear that Christians are to be loving. Jesus expect love toward:
God the Father (Matthew 22:37)
Jesus Christ (John 14:15)
Neighbors (Matthew 19:19)
Enemies (Matthew 5:44)
Peter urged Christians to "Love the brotherhood." (see 1 Peter 2:17) Paul said to owe no man anything, except love (Romans 13:8). Paul also explained--in 1 Thessalonians 4:9--that "you yourselves are taught by God to love one another."
So, let's suppose somebody looking for the Lord concludes--correctly--he needs to find the Church of Christ. He searches online or in a phone book for more information and finds multiple congregations in his small town. What message does that send? If the Lord's people love one another, shouldn't they be able to get along well enough to assemble as one congregation?
Or what if he arrives to a congregation that fights over silly things like the color of the carpet or the new song book? Or a church that has political infighting? These and other "minor" things have caused major discord in congregations. It ought not be.
Jesus wants love to be a defining characteristic of his people. May we do our part to honor his desire.