Be kindly affectionate to one another with brotherly love… Romans 12:10
Paul gives short commands to believers. In verse 9, he writes that our love for each other must be sincere. In this verse he writes of love as a kind of devotion to a sibling. We must love each other with a brotherly affection. Those in Christ are truly brothers and sisters. God adopts us as His children, welcoming us into His family. That family includes everyone who knows God as Father. The love of God is the foundation for this commitment.
Paul’s second command in this verse instructs us to compete in displaying this love and affection. We are told to outdo one another in showing honor to each other. One of the signs of spiritual maturity that Paul lists here is devotion to others who are our fellow Christians. This means that we genuinely rejoice when others are honored. All Christian relationships, even with unbelievers are meant to be horizontal and not vertical. If each of us follow this, everyone in Christ would always feel deeply honored by others.