In John 13:34-35, Jesus says:
34"I give you a new command: Love each other. You must love each other like I loved you. 35All people will know that you are my followers if you love each other." (Easy-to-Read Version)
King James Version: 34A new commandment I give unto you, That ye love one another; as I have loved you, that ye also love one another. 35By this shall all men know that ye are my disciples, if ye have love one to another.