Actually, the reason is really quite simple, but the solution is not so simple since we often don't want to follow the steps to solve it. As mere mortals, relegated to that status following the first sin committed by Adam and Eve when they ate of the forbidden fruit, we find ourselves so enamored with the things of this world instead of the guidance provided us from another world and as we grow and gain more earthly knowledge, the lack of incorporation of God's knowledge leaves us with a void we cannot fill. It is blocked by earthly desires which run counter to God's wishes for us and thus crowd Him out. The answer is not one many wish to consider, but what is required to overcome sinful desires is to open ourselves to the knowledge that God holds for us in His word and then temper worldly knowledge with God's perfect knowledge that comes from another world, His Kingdom.
While we might be smart, unless we add His guidance and heavenly knowledge to even the greatest of earthly knowledge, we can never truly live up to what he expects of us. This applies to human knowledge at all levels and the power of His knowledge is so much greater that a man like the Apostle Paul was able to clearly understand His truth and grace because he was granted the gift of heavenly knowledge. From his beginnings as a strict enforcer of the traditional Jewish faith, witnessing the stoning of the first Christian martyr and then spending his waking hours putting believers in jail, Paul was given God's knowledge and the gift of imparting it to others and it changed him dramatically into a true servant of the Lord.
Perhaps by today's standards a better way to understand it is to look at two highly trained professions and how they can be changed in outlook and result by not limiting themselves to worldly knowledge. For these examples, let's look at engineers and medical doctors and a couple of examples of how this might work or fail. We'll look at them separately.
Imagine a professional engineer or an architect hired by a developer to come up with a plan to design a development for a beautiful beach town while keeping it beautiful by God's standard, a place that all could be proud of including the current residents who are concerned about being priced out of their own homes as is so often the case. The engineer who used his earth-learned knowledge plus the ultimate knowledge of God would recommend a plan which would afford the developer to make a reasonable profit and pay for itself by its beauty while not destroying the lives of others. Sadly, it likely wouldn't meet the desires of the developer nor his supporters from the local Chamber of Commerce who seek the maximum in quick return on tax dollars and have already planned a property assessment proposal for the politicians in their private-public partnership. Despite arguments to the contrary, that new standard for spending money is a fairly recent standard which always hurts the little guy who doesn't have the big bucks for the legal processes he would need to fight for his rights. Should the engineer or architect fail to follow that guidance of the powerful he likely would find himself out of work and perhaps unemployable in his field.
Or maybe it's the physician who has a very sick patient with good insurance but not a Cadillac plan for a major life threatening medical condition which can be cured.Unfortunately, the cure is so costly, to a large degree caused by the bureaucratic procedures and oversight costs that it is out of the patient's reach. The doctor is a wizard in the earthly medical field of study but also believes in the Divine nature power of God's higher power of knowledge and wants to employ such a combined strategy of treatment using a much less costly regimen. But likely now working for a large, bureaucratic medical organization as opposed to the old traditional medical practice using the principles of the Hippocratic oath, the doctor is overruled at all steps in the process by his financial and administrative masters who see the patient as nothing more than a number on a chart. He can either get the treatment and perhaps end up homeless or he can die. He likely would choose to die for the requirement would cure him but there would be no way for his family to survive under the circumstances. And while neither option is a good solution, these types of situations happen every day.
Now, I don't want the reader to take these situations literally for they are just an extreme example posed to show the dilemma we all face today within the constraints of a secular society which doesn't take into consideration the capabilities and wonders of the Living God. But just think how different things might be if not only the doctor and the engineer tried to live and work knowing both the knowledge of their human world and with the discernment that comes with an understanding of God's other worldly knowledge. If the medical administrators and bean counters as well as the developer, Chamber of Commerce and the lawyers and politicians shared that heavenly knowledge base as well, what a wonderful world it would truly be. It's at least something the think about, don't you think? God our wonderful Creator has the answers to all problems; we just have to seek Him out and listen to His revelation. How sad that so many of us don't even seem to care. What a waste of special knowledge.