I John 2-3

“See how great a love the Father has bestowed upon us, that we should be called children of God” (3:1).  John wrote to help believers understand how to live as “children of God.”  He assured them that if they sinned, they had an advocate with the Father, “Jesus Christ the righteous” (2:1).  And as they came to know Jesus more, they would keep His commandments more (2:4-5).  John warned them, too, that following Jesus in the way of self-sacrificial love might cause the world to hate them (3:13).

God’s commandment is simple: “that we believe in the name of His Son Jesus Christ, and love one another” (3:23).