When I get discouraged or start to lose my way in this business of theology, the first place I go is back to the Scriptures and pray. After that, I often go to Barth.
For all [God] does, there is a good reason. He exercises law and justice when he makes the theologians, the church, and the world realize that even the best theology is in itself and, as as such, a human work, sinful, imperfect, in fact corrupt and subject to the powers of destruction. It is God’s right to show that, in itself, this work is wholly incapable of service to God and his community in the world. Only by God’s mercy can it become and remain fitting and useful….And God’s rejection, deposition, judgment, and negation strike, punish, and overturn the very foundation of everything which proves to be continually sinful, imperfect, corrupt, and subject to the power of nothingness – even in man’s best works in and man’s best theology.
All theological work can only become and be fitting and useful before God and men when it is repeatedly exposed to and obliged to pass through this testing fire. This is the fire of the divine love, but it is also a consuming fire. All that makes theological work pleasing to God and beneficial for the world is what remains of gold, silver, and precious stones, according to 1 Corinthians 3:12.
The passage of theology through this fire is its temptation. Compared to this, even its most desperate solitude or its most radical doubt is only child’s play, for what might remain of theology after this fire? The theologian can only have God for himself when he has him continually against himself. And only when he reconciles himself to this can he, for his part, also desire to be for God.
K. Barth, Evangelical Theology: An Introduction, 138-9.