"Every theological idea which makes an impression upon you must be regarded as a challenge to your faith. Do not assume as a matter of course that you believe whatever impresses you theologically and enlightens you intellectually. Otherwise suddenly you are believing no longer in Jesus Christ, but in Luther, or in one of your other theological teachers.One of the most difficult experiences for a theological instructor to combat arises out of the fact that good, respectable theology - by no means only dissolute theology bristling with heresy - for the reasons I have mentioned, threatens our personal life of faith. Faith must mean more to us than a mere commodity stored in the tin cans of reflection or bottled in the lecture notebook, whence at any time it may be reproduced in the brain."
- Helmut Thielicke, An Exercise for Young Theologians (Grand Rapids: William B. Eerdmans Publishing Company, 1962).