Why is love for the brethren important for Christians?

Love for fellow believers is a hallmark of genuine Christian faith, as emphasized by 1 John 4:21, which states, 'This commandment have we from him, That he who loveth God love his brother also.' This mutual love is not only a command but a reflection of the transformative love that God has for His people. When we love one another, we display the reality of God's love within us, revealing that our hearts are aligned with His. Furthermore, in 1 John 3:16, it states, 'Hereby perceive we the love of God, because he laid down his life for us, and we ought to lay down our lives for the brethren.' Thus, this love fosters unity, edifies the church, and serves as a powerful testimony to the world about the truth of the Gospel.