“Dear friends, since God so loved us, we also ought to love one another.”
In Jn.13:34 Jesus gave us a new command to love one another as He has loved us! As plain as this command seems to be, we still have trouble understanding and obeying it. Love does not mean we must like one's personality or approve of their character. Of course love includes our emotions, but love is more than our mere feelings. Love is best defined by actions that are motivated by a desire to please and glorify God. Love must begin with loving God with all our ability! Brotherly love means we desire to do no harm, but genuinely wish to bless and treat one another well. The very best way to understand this command to love one another, is to study and mimic the life of Jesus Christ.
The "one another" passages found throughout the New Testament are a big help too, because they breakdown the command to love into practical ways of how we should view and relate to each other. Remember, the Lord's Church is not about performing rituals for rituals sake. All our assembly functions are tools that God has designed to help us establish and mature our relationships with Him and one another in our everyday lives.
In Rom.12:1-8 Paul shows how we (as objects of God’s mercy) are to serve and worship God by relating to each other as members together of the Body of Christ. Just as it is in our human bodies (note 1Cor.12), each member of the church is connected, gifted, honored and important to it's spiritual health and function. Then in Rom.12:9-13 Paul shows the motive, or unction behind the function, of the church as a united body. He says we are to be "devoted to one another in brotherly love." This passage stresses our relationships together as the family of God.
Earthly families know what this means. Yes, natural relatives show brotherly love because of their love for common parents and ancestors. Likewise, Christians are devoted to each other by being kind and affectionate, preferring each other and cherishing our relationships together as children of our Heavenly Father. As children of God, we are not to limit our love to the church because He does not limit His love to the church Lk.6:35f. The church is God’s chosen witness of His love for all people! Paul sums it up well for us in Gal.6:10, “Therefore, as we have opportunity, let us do good to all people, especially to those who belong to the family of believers.”