What does the Bible say about brotherhood in Christ?

Brotherhood in Christ is a spiritual relationship that is distinct from earthly familial ties. In Matthew 12:46-50, Jesus emphasizes that those who do the will of His Father are His brothers and sisters. This relationship is formed not by natural birth but through adoption, as seen in Galatians 3:26, where we are called children of God by faith in Christ Jesus. True brotherhood, therefore, is rooted in the grace of God and the shared faith in Jesus, not merely in social or physical connections.