The Iglesia Ni Cristo believes that members of the true Church Of Christ should observe the brotherhood. Christ established a brotherhood inside the Church Of Christ (Matt. 23:8). That is why members of the Church address one another as brother and sister.
Iglesia Ni Cristo members should love one another as commanded by Christ and as taught by the Apostles. This shows that they are the true disciples of Christ (John 13:34-35; I Pet. 2:17).
It is evil to hate any brother in the Church. Whosoever hates his brother in the faith is considered a murderer and shall not attain everlasting life (I John 3:15).
To maintain the love for brotherhood in the Church, members who have misunderstanding or disputes are commanded to reconcile (Matt. 5:23-25; Eph. 4:32).