Why is being called a holy brother important for Christians?

The designation of 'holy brethren' in Hebrews 3:1 is crucial as it reflects a believer's identity and standing before God. This title indicates that believers are set apart by God's choice and, through the sacrifice of Christ, made holy. It underscores the relationship between Christ and His followers, highlighting that they share in His holiness. Understanding this identity is vital for Christians as it shapes their relationship with God and influences their conduct in the world, leading them to live in response to the grace that has made them holy.