What does the Bible say about love among believers?

In John 13:35, Jesus emphasizes that love among His followers is the identifying mark of true discipleship: 'By this shall all men know that you are my disciples, if you have love one to another.' This love is not merely an emotion but a commanded action that reflects the character of Christ. It is through love that believers demonstrate their connection to God, who is love itself (1 John 4:8). Genuine love among brethren is essential in the life of the church, confirming their transformation from death to life (1 John 3:14).