From Thomas a Kempis:

What good does it do to speak learnedly about the Trinity if, lacking humility, you displease the Trinity? Indeed it is not learning that makes a man holy and just, but a virtuous life makes him pleasing to God. I would rather feel contrition than know how to define it. For what would it profit us to know the whole Bible by heart and the principles of all the philosophers if we live without grace and the love of God? Vanity of vanities and all is vanity, except to love God and serve Him alone.

I could be wrong, but I think the estimable Kempis is on to something here. It might even be the same thing that Paul was on to in 1Cor 8:

Anyone who claims to know something does not yet have the necessary knowledge.

Of course, this verse is often an excuse for trite anti-intellectualism and general silliness. That's not what this is about. Bonhoeffer makes the point (in Cost of D.) that, when Faust says "I now do see that we can nothing know" he does so as someone who has learned quite a bit. He also points out that, if a college sophomore said the same thing, it would be the heart of foolishness. Neverthless, probably words worth remembering.