This verse continues the repetitive instruction, of the good versus evil conflict, that resides within each and every individual.
It does not provide for a scapegoat, nor for a justification or excuse of doing the things that we do.
But it does further emphasize the power of sin and its influence over us, such that if we have no resources to combat sin, namely Bible doctrine in the soul, then that sin is more powerful than our resolve.
This principle makes it clear that there is no philosophy, no method, no approach, no resource within the human experience, that will allow us to combat sin and evil, and come out a winner. Defeating sin on our own, is an impossibility.
You cannot rid yourself of it by means of any kind of special food diet.
You cannot rid yourself of it by means of any kind of exercise.
You cannot rid yourself of it by means of any kind of dedication to philosophy, or religion.
You cannot rid yourself of it by means of science, or logic, or human reason.
When the body is tainted, and headed for corruption, it is impossible to terminate or reverse that corruption.
Since there is nothing within the human realm for combating sin and evil and death, then we have to look outside the human realm, for the solution.
And that solution of course is faith in Christ for salvation, a daily study and Bible doctrine for the development of spiritual resources, and the consistency of functioning within the spiritual life, every day, throughout ones entire life.
Even still, believers are still subject to the influences of sin.
But what we do have, is salvation, and when we leave this world, then all of that old stuff will be left behind.
Study [by instruction],
to show thyself approved [spiritually mature]
a workman [student]
that need not be ashamed [ignorant],
rightly dividing [learning, understanding, discerning]
the word of truth [Bible doctrine].