The Greek word underlying “carnal” is sarx, which Strong's Concordance says refers literally to the meaty part of an animal or man. However, it has several figurative usages that commonly appear in the Bible.
The Interpreter's Dictionary of the Bible adds that sarx “is either the equivalent of the English word 'material' or describes human nature when under the domination of its lower, unregenerate impulses.” “Carnal” describes the way we humans think and act without the influence of God's Holy Spirit that we receive when we are called, repent, and are converted. The carnal mind focuses on using circumstances in life to please the self.
In many modern translations, sarx is often rendered as “flesh,” its literal meaning. In the context of Romans 8, it is translated as such in the New King James Version to clarify that spiritually, there are two classes of people. Those who live according to the flesh allow their lives to be determined by their sinful nature. They set their minds on—are most deeply interested in, constantly talk about, engage in, and glory in—things that pertain to the self.
Those in the other category live according to the Spirit. They submit to the Holy Spirit's influences, concentrating their attention on, specializing in, and choosing what is important to God's Holy Spirit. In the conflicts between the pulls of the flesh and the influences of God, the first group sides with the self, and the second group sides with God, despite knowing that choosing that way may entail considerable sacrifice.
In Romans 8, Paul reminds church members that it is impossible to be on both sides at once. This choice is basic to our attitudes and sets the direction of our lives: We are either on God's side or sinful human nature's side. If a person persists in siding with the flesh, which is worldliness, then he must expect the world's doom. Conversely, if the things of God and His Kingdom are a person's chief concern, he can expect God's love to be shed abroad in his heart (Romans 5:5) and his future to be full of unspeakable joy, as Paul later declares.
In the apostle Paul's writings, “flesh” clearly indicates spiritual weakness. He teaches us that a person living by the flesh cannot be justified before God or please Him because the flesh does not appreciate God's priorities. Living with a fleshly outlook leaves an individual vulnerable to the power of sin to excite him to temptations, self-gratification, pride, pursuit of praise, envy, selfishness, impatience, and a definite unwillingness to sacrifice for spiritual well-being. As Paul teaches, the spirit may be willing, but the flesh is weak because it is not inclined to believe God.
It is the flesh, stirred to action by Satan, that drives this world. Even so, we must be clear on an important truth: Satan cannot make us sin. Scripture says unequivocally that the sins committed belong to those who committed them. Adam's and Eve's sins were not forced by Satan. He reasoned with Eve, and she chose to believe what he suggested and then transgressed. Neither was Adam forced by Satan to sin, nor was he deceived as she was. He chose to follow his wife into sin without Satan's arm-twisting.
John W. Ritenbaugh
Leadership and Covenants (Part Seven)