Why is loving our brothers in Christ important?

In 1 John 2:9-10, the significance of loving our brothers is highlighted, stating that those who claim to be in the light but hate their brothers are still in darkness. This love is not merely a suggestion but an essential aspect of the Christian faith, signifying our transformation and new identity in Christ. Loving one another provides evidence of our true connection to Him, as love demonstrates the light of Christ within us. This mutual love among believers not only strengthens the church but also acts as a witness to the world of God's love and truth.