John Piper has written a powerful book on the life of the mind entitled Think. Piper is easily my favorite writer, and this is possibly my favorite book of his. Here is an excerpt from the book on why our head and our heart should both be stimulated in our faith:
God has given us minds and demanded that we use them in understanding and applying his Word. And God has given us emotions which are equally essential and which he has commanded to be vigorously engaged in his service.
If we neglect the mind we will drift into all sorts of doctrinal error and dishonor God who wills to be known as he is. And if we neglect the heart we will be dead while we yet live no matter how right our creed is.
Often I run across people who are either more logically-driven or more emotionally-driven in regards to their faith. There are problems that can arise if we focus too much on one or the other.
Thinking Too Much
This can lead to 1) an issue of intellectual pride, and 2) legalism. One problem that exists in theological circles is that people tend to feel that they have so logically figured God out that they frown upon or belittle anyone who does not “get it.” This mindset drives us into idolizing something other than God and causes us to focus on the dogmatic and not the spiritual. Over-thinking makes us a sort of mindless robot, going through the motions but not taking seriously the supernatural, unexplainable work of God. We must be able to live in the tension of our finite minds and God's infinite mind, understanding that we cannot fully grasp his endless wonders. This realization should cause great humility and admiration of our matchless King.
Feeling Too Much
The main issue here is that people get so caught up in their last emotional high that they are disappointed when that high fades out. The Christian faith is not always crying during worship or an insatiable desire to read the Word; often times it is gut-wrenching and plain exhausting. You will not always “feel like” living obediently or dying to self. This is where sound, basic theology of who God is and what he has done can carry us through the dryness of life in a fallen world. We must be able to use our knowledge of God to remind our hearts that his glory is worth fighting for and that he has not lied or drawn us to himself in vain. Emotional reactions to circumstances have led me to a tainted view of a good God.
My prayer is that God would not only tune my mind to him, but tune my heart as well. The gospel frees us to take both our thoughtful doubts and heart-led burdens to the throne of grace. He is there, he promises to provide. If our minds and hearts are both in rhythm with God - albeit imperfectly - we will be a grave danger to Satan’s work in this world.