In the core of our being, we are driven through life by something that is complex and unknowable; our heart. Sometimes it is called our soul, some refer to it as our essence, but in
the Word it is referenced as our "heart" so let's go with that. The Bible is full of references and instructional wisdom about this essential piece of us: it is our character, it is what defines us, it is who we are. We are told that we cannot trust our heart because 'it is wicked, deceitful, ....who can know it!' Our heart is easily broken and easily hardened, it can be like stone or it can melt like wax. It is capable of empathy, sympathy, and great courage and equally susceptable to blindness, greed, and paralyzing fear. When the apostle Paul spoke to the dichotomy of "doing the things I would not do, and not doing the things I know I should", he is defining the the mystery of our heart's and the struggle we face in answering God's call upon it.
The heart is intricately partnered with our mind: the portion of ourselves that reasons, remembers, extrapolates, conjectures; the hard drive that navigates us through our day. Our heart is the "feeling" part of us while the mind is the "thinking" part. This is the simple version of "us" as agreed upon by science and culture. We are a biological machine that lurches around with our brains computing what we are seeing and doing, while it trys to deal with the troublesome software application called the "heart" that complicates every decision with concepts like sorrow and kindness, parameters of selflessness and love. The world has no time or patience for the complexity of our constitution, our blend of reason and feeling: it is much easier to call the Heart and Mind two seperate entities and science naturally elevates the brain above the heart.
Intrinsically, we know the truth of our complexity. God has made us in His image and we realize that we have been "fearfully and wonderfully" made. There is an element of "Him"
alive in us: it is what He calls back to Himself, it is His claim on our hearts and lives. Our problem with the reponse and with knowing and understanding that call is sin. It has been between our hearts and God and it has made us confused and confounded: sin has corrupted our hearts and minds so that we are subject to the wrestling match that Paul described so eloquently. Even though we are redeemed from sin by Christ, our sanctification is incomplete and we struggle to reconcile our heart's longing to emulate Him with our old nature: painfully aware of our inadequacy but joyous and hopeful that we might succeed.
This mysterious duality seems to intensify with age and wisdom. Having more experience and resources would seem to guarantee some semblance of progress in "knowing the heart"
in the same way a mechanic of 30 years understands machines better than a teenager.
In matters of the heart, the man is wise who professes to know nothing.
Jeremiah 17:9 (Amplified Bible)
9The heart is deceitful above all things, and it is exceedingly perverse and corrupt and severely, mortally sick! Who can know it [perceive, understand, be acquainted with his own heart and mind]?(A)