Left to itself, our brain does not think in accordance with the truth.
"Be renewed in the spirit of your mind" (Ephesians 4:23).
The Holy Spirit must illuminate and energize a new way of thinking in the minds of all believers, enabling us to put away the carnal mindedness that is death, and to put on the spiritual mindedness that is life and peace (Romans 8:6). Our Lord is incessantly working to accomplish this, and our primary responsibility is to believe that He is doing so. However, we have another role in the renewal because God has no interest in merely programming robots. He rather seeks to engage us in the living relationship made possible by the wonder that "God hath sent forth the Spirit of His Son into your hearts, crying Abba Father" (Galatians 4:6). Such union and communion with our Heavenly Father requires active response on our part, as enabled by the Holy Spirit, and as received by application of God's gift of the Lord Jesus Christ.
"When Thou saidst, Seek ye My face; my heart said unto Thee, Thy face, LORD, will I seek" (Psalm 27:8).
Certainly the search for the face of God begins in His Word, and continues forevermore. "In Thy light shall we see light" (Psalm 36:9). Consistent reading and pondering of Scripture fans the flame of illumination in our hearts and minds, directing our thinking into the light of Truth. However, the renewing of our minds results primarily from applied knowledge, as it were, or the consistent determination to use the countless opportunities in our everyday lives to "think on these things" (Philippians 4:8). Indeed, it is not enough to simply read the Bible, or study it, or even memorize it. We must believe it, and submit ourselves unto its revealed Lord in living experience if our thinking is to be progressively changed from carnal to spiritual mindedness.
The Spirit of God enables this pursuit, even as we consciously and willingly run the race. The Psalmist knew this glory of relationship, as opposed to programming. "I will love Thee, o Lord my strength" (Psalm 18:1). "I will" declared David to the Lord also affirmed as the "my strength" of the commitment. This day and this moment offers to us such possibility of living and active relationship whereby we literally walk with God. It is the opportunity of a lifetime, and this particular epoch given to us by grace will not come our way again. Let us therefore not miss the many ways in which we will be given to think in accordance with the Word of God, and thus to believe and obey in the power of the Holy Spirit.
"Let the words of my mouth, and the meditation of my heart, be acceptable in Thy sight, O LORD, my strength, and my redeemer."