I maintain that a biblically balanced Christian has both a full head and a full heart, radiating both spiritual light and heat.
If absolutely forced to have only on or the other, we must choose the burning heart. If we have the truth in our head but our hearts are not right with God, an awareness of truth will only magnify our guilt before Him at the judgement. But if we have properly responded to the gospel from the heart, in the end we shall be saved even though the rest of our doctrinal understanding is shallow or muddy. Not only would I choose that option for myself, but I would prefer that for those I pastor as well. It’s much harder to get a ship out of the harbor than to correct one on the sea that has drifted off course.
But let us be both out of the harbor and on course. Christians must realize that just as a fire cannot blaze without fuel, so burning hearts are not kindled by brainless heads. We must not be content to have zeal without knowledge.
Does this mean we must be brilliant to be Christians? Absolutely not. But it does mean that to be like Jesus we must be like learners even as He was at only age twelve, “sitting among the teachers, listening to them and asking them questions. Everyone who heard him was amazed at his understanding and his answers.” Does this mean we must have several diplomas handing on the wall to be first-rate-Christians? It certainly does not. But it does mean that we should discipline ourselves to be intentional learners like Jesus, of whom it was marveled, “How did this man get such learning without having studied?”
– from Spiritual Disciplines for the Christian Life