Jesus makes the same connection when challenging His enemies on being superficial and legalistic: “The good person out of the good treasure of his heart produces good, and the evil person out of his evil treasure produces evil, for out of the abundance of the heart his mouth speaks” (Luke 6:45). The connection is extended from the heart to our words and behavior.
This is the reason that you cannot “argue” someone into the kingdom. Yes, Christianity is quite logical and rational, but neither can be seen without a transformed heart. The heart, one’s operating system, must be transformed. This is exactly what the Lord promises in Ezekiel 36:26: “And I will give you a new heart, and a new spirit I will put within you. And I will remove the heart of stone from your flesh and give you a heart of flesh.” It is only when we are given a new heart that the transformation of our thoughts can truly begin.
Both mind and heart are involved in this process of transformation. Concerning the mind, it is necessary to know the facts of the gospel (notitia). It is not just enough to know the facts, but one must affirm the facts of the gospel (assensus). It is also necessary that this truth be warmly embraced and received (fiducia). This final embrace of the truth engages the heart in a full-orbed description of saving faith.
All this leads to a new orientation to all of life. From this point on, we are called to strengthen and fortify our hearts for God through the engagement of our minds. The New Testament contains some remarkable language about this. In his letter to the Romans, Paul writes, “Do not be conformed to this world, but be transformed by the renewal of your mind, that by testing you may discern what is the will of God, what is good and acceptable and perfect” (Rom. 12:2). The word translated “transformed” is the word from which we get our word metamorphosis. When we hear that word, we often think of the gradual change that occurs in the development of a butterfly. The similarity to us is that there is a gradual transformation of the way we think. We are no longer to be earthbound in our thoughts, but we are to develop a new perspective that expands from the horizontal to include a godly vertical perspective. Paul puts it this way in his letter to the Colossians:
If then you have been raised with Christ, seek the things that are above, where Christ is, seated at the right hand of God. Set your minds on things that are above, not on things that are on earth. For you have died, and your life is hidden with Christ in God. (Col. 3:1–3)
It is important to recognize that Paul’s line of argumentation is not intended to communicate an approach that is “so heavenly-minded that it is no earthly good.” Quite the contrary: looking back at his words in Romans shows us that the renewal of our minds is designed to help us “discern what is the will of God, what is good and acceptable and perfect,” with the implication that it will translate into the way of life that reveals our love for our Creator and Redeemer. While our love will never be perfect this side of heaven, He has given His Spirit and His Word to feed the flame in our hearts and minds until we meet Him.