One of the most striking aspects of the Johannine writings is the way in which they view the world through the lens of apocalyptic. The Gospel and Epistles of John see the world as utterly rent by cosmic conflict. The church in the Johannine writings is an island of the order of God that has broken down into the cosmic anti-God system which is the “world.” Thus the church is the site of conflict between the forces of God and the forces of the Devil.
The Johannine writings understand the eschatological tension of the church in the world quite differently than the “already/not yet” of Paul and the Synoptics. In Paul especially the line between the old age and the age to come runs through the church and through each Christian (see esp. Rom. 7-8). For John by contrast, the church is the divine reality of God that has descended down to earth, invading, and interrupting the evil system of the world. Thus, the eschatological tension the church lives in is not within the church but between the church and the world. Thus the holiness of the church is vital in the Johannine writings. The church is the presence of the heavenly kingdom of God which is dynamically invading the world, translating people out of the world of death into the new world of life. (cf. 1 John 3:14)
Deriving from its apocalyptic orientation, the Johannine literature centers on calling Christians into a life of total love for one another. Love is the ultimate definition of who and what God is (1 John 4:7ff). Therefore, we are called to participate in, imitate, and abide in the form of love manifest in Christ, eschewing any other way of being in the world. Thus for John holiness is defined as an exclusive orientation towards mutual love as the Christian mode of action.
Moreover, this ethic of absolute love derives from John’s apocalyptic worldview. Loving one another is how we participate in God’s invasion of the world that began in Christ’s death and resurrection. Loving one another brings us into God’s own being, unites us with Christ, and grants us eternal life, which, for John simply is union with God in the perichoretic relations of the Godhead (John 17:21-23). Thus, the ecclesial reality of mutual love is the reality of life displacing death, it is the eschaton embodied in the world. The Johannine ethic of mutual love is ultimately an ethic which demands and implies a theological understanding of history. It calls us to incorporate any and all interruptions into our life through a thoroughgoing practice of love, believing this act to be the only mode of being that is in step with God’s eschatological action, which is bringing creation to its transfiguration and consumation.