In Your Mind Matters, John Stott discusses the practical relevance of pursuing a Christian mind.

1. Worship

Christians do not worship ‘the unknown god’ (Acts 17:23).  They are to worship God ‘in truth’ (Jn 4:24).  We are to praise his ‘name’, implying that we are to know and understand his true being and character.  Rational enquiry is found throughough the Psalms: including the study of God’s works in nature (Psa 104) and in history (Psa 77).

To worship God with the heart (see Mk 7:6, quoting Isa 29:13) is to worship God not merely with the emotions, but with the whole of our personalities.  Heb 4:12 refers to ‘the thoughts of the heart’.

To worship God ‘in spirit’ is to rely less on outward forms, more on inward devotion.  And notice the close association with worship ‘in truth’.

Neither in private nor in public worship is the mind to be by-passed.  Reason is to be engaged, not set aside.  Forms or worship which emphasise senses and emotions at the expense of thought are not superior forms, as some imagine.  Rather, they open to door to mysticism and fanaticism.

2. Faith

Let us eschew the false antithesis between faith and reason.  Scripture contrasts faith and sight, but not faith and reason.  In fact, true faith is essentially reasonable because it trusts in the revealed character and promises of God.

Biblical faith is neither mere optimism nor positive thinking.  It is not faith itself which brings about change.  What is important is the object of faith.

3. Holiness

The truth does indeed set us free (Jn 8:32), but it does not free us from the responsibility of living holy lives.  Now, in order to holy lives, the first requirement is to know what God requires of us.  Scripture often traces sin back to the deceipt of the mind.  If we are to live straight, we are to think straight.  It is by the renewal of our mind that our character and behaviour are transformed (Rom 12:2).

But the focus is not simply on what we much do for God, but also on what he has done for us.  He has made us his children, temples of the Holy Spirit, heirs of his glory.  In his appeals to the Romans and the Corinthians, Paul repeatedly asked: ‘Don’t you know…?’

Growth in knowledge is essential to growth in holiness.

4. Guidance

We may distinguish between God’s general will (applicable to all believers) and his particular will (specific to each individual).  The first is revealed in Scripture; the second is not.  In order to discern God’s particular will for us, we  must apply our minds, not relying on irrational impulses.  The guidance promised in Psa 32:8 does not by-pass the mind, as the very next verse shows.

5. Evangelism

Coming to faith in Christ presupposes that people have heard of the message of Christ (Rom 10:17).  So evangelism cannot rely on emotional or empty-headed appeals for decisions.  If we are to call on Christ, we need to understand who he is.  Paul was committed to persuasion and argument (Acts 17:2–4; 18:4; 19:8–10; 2 Cor. 5:11).  The New Testament describes conversion not only as a response to Christ, but as a response to ‘the truth’ (Rom. 6:17; 2 Thess. 2:13; 1 Tim. 2:4; 4:3; Titus 1:1; 1 Pet. 1:22; 2 John 1–4).

This being so, there is an urgent need for more thinkers who will be serve the cause of Christ as teachers, authors, journalists, and so on.

When Paul eschews ‘lofty speech’ or ‘wisdom’ (1 Cor 2:1-15) he is not renouncing doctrinal content or rational arguments, but only the empty, worldly intellectualism that despised the message of Christ crucified.  The Corinthians regarded that message as ‘intellectually foolish (incompatible with wisdom), religiously exclusive (incompatible with tolerance), personally humiliating (incompatible with self-esteem), morally demanding (incompatible with freedom) and politically subversive (incompatible with patriotism).’

This not to say that Christianity is only for educated people.  No: our presentation of the gospel does not need to be academic, but it should be rational.  True, only the Holy Spirit can savingly enlighten the mind, and he does so not by side-stepping the truth, but by enabling us to see it more clearly.

6. Ministry

There has been a renewed interest in spiritual gifts over the past 50 years or so.  But all the gifts are for the common good, and the gifts to be most valued are the teaching gifts, because it is by these that the church is most effectively built up.  The church’s elders are to be apt to teach.

But God never intended knowledge to be an end in itself, but rather a means to an end.

See also: Chester, Tim. Stott on the Christian Life (Theologians on the Christian Life).  Crossway.