Love One another
Jesus is very clear about this requirement of loving one another. John 13:34-35 states "I give you a new command: Love one another. Just as I have loved you, you are also to love one another. By this everyone will know that you are my disciples, if you love one another.” Love is the main ingredient in one receiving the truth of the gospel.
No Greater Love than this.....
30 Love the Lord your God with all your heart, with all your soul, with all your mind, and with all your strength.[a][b] 31 The second is, Love your neighbor as yourself.[c] There is no other command greater than these.” Mark 13:30-31