Overbeck on being a child

As Overbeck had said: "Christians must be children, but they cannot.  That is the way it should be, for the challenge is meant for a different world from the one in which contemporary church and Christianity exist.  from Karl Barth: A Theological Legacy, Jungel, p. 61.

(I need to learn German.  There are a lot of fascinating works I can only read 2nd hand right now.   Would the Rosetta Stone help at all :)  I need to learn me up better Spanish, too.)