“A new commandment I give unto you, That ye love one another; as I have loved you, that ye also love one another. By this shall all men know that ye are my disciples, if ye have love one to another.” - John 13:34, 35.
Apart from knowledge of the truth, Christians must love one another and thereby “grow up into him in all things, which is the head, even Christ”. (Ephesians 4:15). Our Saviour stated clearly while on earth that the mark of true disciples is the love they have for one another. The love is demonstrated in practical terms by way of seeking the interest of one another, sharing in the joy and pains of our fellow believers; (Philippians 2:4,5; 1 Corinthians 12:26); supplying the needs of another believer or assisting him when he is in trouble, (James 2: 14-17; 1 John 3:17,18); not doing any harmful or injurious thing to the other person but treating others as one would like to be treated. – Romans 13:8-10.
St. Paul stated: "And this I pray, that your love may abound yet more and more in knowledge and in all judgment; that ye may approve things that are excellent; that ye may be sincere and without offence till the day of Christ." (Philippians 1:9,10) Some of us have a long way to go in terms of love for ourselves. If we have the truth but do not love one another, then we are incomplete. We must work on this and do to others as we would want them to do to us. (Matthew 7:12) St. Paul wrote, "And the Lord make you to increase and abound in love one toward another, and toward all men, even as we do toward you..." -1 Thessalonians 3:12, 13.