Barth, CD I/2, p. 711:
To be a member of the Church in relation to Scripture which founds, maintains and rules the Church, means not only to hear, receive and believe the Word of God, and so in one's own life to become a man directed and consecrated by the Word; more than all this it means to take seriously and understand as one's own responsibility the effective operation of the Word, its being continuously expressed and heart, its being continuously proclaimed and made fruitful.
The Word of God wills always to be newly and more widely heard in the Church, and beyond the Church lies the world, where by the Church it also wills to be always heard. Because of his freedom which is grounded in this Word, a member of the Church cannot retain a passive, indifferent and merely waiting role in face of this will of the divine Word, as though anyway, in its own time what has to happen will happen. Certainly, it will happen, but not without us. We have seen that we ourselves stand at the present end and goal of the way which the Word of God takes in approaching men. We ourselves are thus present when the way leads on into the Church and the world.
Called by the Church into the Church, we ourselves become the Church into which we are called. Yet we cannot merely note that the Church is calling and wait to see whether and how far the Church will continue to call. Rather we ourselves have become the Church in person, and as such have been made responsible for its future. And this means in concrete terms that we are responsible participants in the great event by which Holy Scripture lives and rules in the Church and in the world.