Barth, CD I/2. p. 808:

The truth which the Church has to preach will not be the truth of God if it does not have also its own characteristic beauty. But this very beauty can seduce the Church into treating it as we do other beautiful things, i.e., a dilettante contemplation and enjoyment. But it is beautiful only in order that its work may be done all the more joyfully. If instead of calling to decision it becomes an object of contemplation, it ceases to be the truth.