When John writes that one should walk as Jesus did (2:6), he goes on quickly to remind his readers that this is not a new commandment suddenly being imposed upon them. He is alluding to Jesus' command that the disciples are to "love each other as I have loved you" (Jn 15:12; compare 13:34). He also calls to mind the statement, "Greater love has no one than this, that he lay down his life for his friends" (Jn 15:13). It was Jesus who gave the command to love—but it was also Jesus who lived it out to the full in giving his life for "his own" (Jn 13:1). Years later when the author reminded his community of this command it was no longer new, but familiar and hence old, committed to them since the beginning. The command to love was part of that message you have heard.
What made the command new when Jesus gave it was not its content. The Old Testament contains the command to love one's neighbor (Lev 19:18), and Jesus quotes it in some of the Gospels (Mt 19:19; 22:39; Lk 10:27). Neither does Jesus have in mind a new kind of love or a new expression of love. The God whom Jesus knows and proclaims is a God of love (Jn 3:16).
But the command to love one another can be called new for two reasons: First, it points to a new example of love, that of Jesus' own life. We see his love most fully manifested in his death on the cross (compare Jn 13:1; 1 Jn 3:16; 4:9-10). Second, Jesus' death creates the new fellow ship in which obedience to his command is possible. Jesus' death is the act by which all God's people can be gathered together (Jn 10:16; 11:51-52; 12:24). The command to love was given and modeled by Jesus, and now it is to be put into action by the believing community (2:8). Through their love for one another they testify that the light brought into the world by Jesus' life continues to shine.
To use an analogy, the Christian community is the school in which we learn to love. Like great musicians who practice tedious drills for long hours, Christians practice their scales at home in order to sing in public. In the community love is commanded and modeled, and here is where it must be lived out and practiced. This does not mean that love is limited to the boundaries of the community. But if the community does not live by the model and teaching of its founder, Jesus, how can it expect others to do so or to hear its call to join with them?
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