…we must understand how our sinful human hearts and minds work. One profound biblical insight we need to embrace is that our heart exploits our mind to justify what the heart wants. That is, our deepest desires precede the rational functioning of our minds and incline the mind to perceive and think in a way that will make the desires looks right…Thus truth is sacrificed on the altar of self-justification….truth has been sacrificed to desire, and the mind has been shrewdly employed by the darkened heart to shroud it’s passions. This is the point of Romans 1:18, “They suppress the truth in unrighteousness.” Truth is held hostage by the unrighteous commitments of the heart. The unrighteous heart then employs the mind to distract and deceive. Doing the evil we love makes us hostile to the light of truth which will expose the evil and rob us of it’s fleeing pleasures. In this condition the mind becomes a factory of half-truths, equivocations, sophistries, evasions, and lies- anything to protect the evil desires of the heart from exposure and destruction. We are all given to this. Our only hope is the transforming work of God in our hearts to free us from the bondage of a hardened heart that produces a futile mind. The root cause is a heart cause, not a head cause. The mind is darkened and made futile by rebellion in the heart. This does not mean that lovers of truth should stop speaking truth and explaining truth and defending truth. But is does mean that we should pray for God to change hearts so that they can see the beauty of truth and love it…”
John Piper, Taste and See