This is an excerpt from the booklet, Your Mind Matters, by John R. W. Stott, originally given as an address at an Inter-Varsity Christian Fellowship conference in 1972.
Why is it important for Christians to use their minds? ... The great doctrines of creation, revelation, redemption and judgment all imply that man has an inescapable duty both to think and to act upon what he thinks and knows.
Created to Think
God made man in his own image, and one of the noblest features of the divine likeness in man is his capacity to think... Man has what the Bible calls "understanding." Scripture assumes and portrays this from the beginning of man's creation. In Genesis 2 and 3 we see God communicating with man in a way that he does not communicate with animals. He expects man to cooperate with him, consciously and intelligently, in tilling and keeping the garden in which he has placed him, and to discriminate -- rationally as well as morally -- between what he is permitted to do and the one thing he is prohibited from doing...
This basic rationality of man by creation is everywhere taken for granted. Indeed, Scripture bases upon it the regular argument that since man is different from the animals he should behave differently: "Be not like a horse or a mule, without understanding."
Thinking God's Thoughts
The simple and glorious facts that God is a self-revealing God and that he has revealed himself to man indicate the importance of our minds. For all God's revelation is rational revelation, both his general revelation in nature and his special revelation in Scripture and in Christ...
The Christian doctrine of revelation, far from making the human mind unnecessary, actually makes it indispensable and assigns to it its proper place. God has revealed himself in words to minds. His revelation is a rational revelation to rational creatures. Our duty is to receive his message, to submit to it, to seek to understand it and to relate it to the world in which we live...
Minds Renewed
Now redemption carries with it the renewal of the divine image in man, which was distorted by the Fall. This includes the mind. Paul could describe converts from paganism as having "put on the new nature, which is being renewed in knowledge after the image of its creator" and as "being renewed in the spirit of your minds." He could go further. A "spiritual" man, a man indwelt and ruled by the Holy Spirit, has new powers of spiritual discernment. He may even be said to have "the mind of Christ." This conviction that Christians have new minds enabled Paul to appeal to his readers with confidence: "I speak as to sensible men; judge for yourselves what I say."
Judged By Our Knowledge
If one thing is clear about biblical teaching on the judgment of God, it is that he will judge us by our knowledge, by our response (or lack of response) to his revelation... This principle of judgment our Lord himself endorsed: "He who rejects me and does not receive my sayings has a judge; the word that I have spoken will be his judge on the last day." ...It is a solemn thought that by our anti-intellectualism, in which we either refuse or cannot be bothered to listen to God's word, we may be storing up for ourselves the judgment of Almighty God.
Conclusion
I have tried to show how basic is man's rationality to the great doctrines of creation, revelation, redemption and judgment. God has constituted us thinking beings; he has treated us as such by communicating with us in words; he has renewed us in Christ and given us the mind of Christ; and he will hold us responsible for the knowledge we have...
Perhaps the current mood (cultivated in some Christian groups) of anti-intellectualism begins now to be seen as the serious evil it is. It is not true piety at all but part of the fashion of the world and therefore a form of worldliness. To denigrate the mind is to undermine foundational Christian doctrines. Has God created us rational beings, and shall we deny our humanity which he has given us? Has God spoken to us, and shall we not listen to his words? Has God renewed our mind through Christ, and shall we not think with it? Is God going to judge us by his Word, and shall we not be wise and build our house upon this rock?