The ONE DISTINGUISHING MARK of TRUE DISCIPLES of CHRIST: "A new commandment I give to you, that you love one another; as I have loved you, that you also love one another. By this all will know that you are My disciples, if you have love for one another." (John 13:34-35)
Before our Lord Jesus Christ left for His eternal abode in heaven, He told His disciples that the world will recognize them through one distinguishing mark: their love for one another. During His absence, they were to be governed by the ‘new commandment of love’. This commandment was new because the Holy Spirit would empower believers to obey it, and so it was superior to the old. The old said, “Love your neighbor” (Lev. 19:18) but the new said, “Love your enemies” (Matt. 5:43-44). It called for a higher degree of love: “As I have loved you, that you also love one another” (v. 34), and thus this commandment has a new motive and a new scope. Christ commands us to love each other just as sacrificially as He has loved us! (See Matt. 25:40; Gal. 6:10; Eph. 5:25)
The badge of Christian discipleship is not a cross worn around the neck or on the lapel or some distinctive type of clothing. Anyone could profess discipleship by these means. The true mark of a disciple of Christ is the sincere agape love for other Christians. This requires divine power, and this power is only given to those indwelt by the Spirit! The world should recognize us as the Disciples of Christ because our relationship to each other is permeated with love!
Let us clearly understand that unbelievers recognize the true disciples of Jesus not by their doctrines, or, by their scriptural expertise or, by their ability to perform dramatic miracles, or, even by their love for the lost. They recognize His disciples by their deeds of love for one another. The servant-like, selfless love that Christians display toward one another witnesses to the world that they are true disciples!
A key test of our commitment to Christ and our love for God is indicated by our love for other believers. It is not just our words that express our love, but our attitudes and actions as well. The way to show love to fellow believers is by doing simple acts of service for our fellow believers who have needs. This may include sending notes of encouragement, visiting them, providing them meals, showing them empathy or, even giving them a friendly smile.
Finally, note that Jesus did not say that others would know we are His disciples by what we say, or how we dress, or what we know, or the label of our denomination. He said, “As I have loved you” (John 13:34). Shortly afterward, He laid down His life for His disciples! How does our love to others compare with the love that Jesus has displayed on the cross of Calvary?