An unfaithful Christian suffers the fate of an unfruitful branch.
Thus, all who are brought into close contact with Christ are compared with branches that are in the vine. Some bear fruit; others do not....
each individual who is brought into close contact with Christ and his gospel
For Keener,Most draw from this (the biblical image of Israel as a vine) the implication that John believes that those grafted into Christ, rather than into ethnic Israel, are in salvific covenant with God.
It is through identifying with Christ that believers…are grafted into the historic people of God.
vital Johannine warning against falling away.