The Bible uses spirit to designate an invisible, immaterial, powerful influence whose characteristics are absorbed and then exhibited in the attitudes and conduct of the general population of a given people.
Course is an influence of which we can be much more aware. We can compare it to a path, riverbed, or highway, suggesting a way by which or in which something flows. It is a means to an end, a result, which may be a destination or an action. Course, under the heading "tendency" in Roget's International Thesaurus, has synonyms such as "thoughts," "disposition," "character," "nature," "makeup," "bent," "slant," "frame of mind," "attitude," "inclination," "drift," "mindset," and "perspective." It is helpful to understand "the course of this world" by rephrasing it as "the disposition of this world," "the character of this world," "the nature of this world," or "the makeup [mindset, attitude, perspective, etc.] of this world."
In the apostle Paul's usage of this word, "course" is the whole mass of elements that encompass the conduct and attitudes of the times, the zeitgeist. It would not be the same all over the world because its expression in people would differ depending upon many factors. However, in Paul's writings, its elements will invariably be carnal and evil because the spiritual source, Satan, is always evil.
We can begin to understand this more practically by realizing that someone from France, Germany, Saudi Arabia, or Iraq, though carnal, would not be as inclined to see, understand, and react to a given situation exactly as an American would. The specifics of what affects their minds will differ. Though all are of the world, the things that make up one nation's course will impress themselves on other nationalities somewhat differently.
Regardless of nationality, the course of this world greatly enhances the self-centered pull that we are born with, and becomes our nature. It is from this that we must be converted, the largely unrecognized foundation of our pre-conversion attitudes and conduct, and it is the same force still motivating us when we behave carnally. Despite conversion, it remains within us, compressed like a spring ready to leap into action and reveal itself in carnality once again.
A prime characteristic of this world's course - exhibited worldwide, regardless of culture - is that it is habitually self-centered rather than God-centered. This is due to the underlying spirit beings who are its heart and soul, the key elements in communicating the course of this world into humanity. Through a simple illustration, we can perceive how it became this way. Genesis 1:31 reads, "Then God saw everything that He had made, and indeed it was very good. So the evening and the morning were the sixth day." God's statement of satisfaction in all He had made at the end of the sixth day of creation includes Adam and Eve's nature, as by this time they were already created.
Thus, in the beginning, mankind's nature is designated by our Creator as, "very good." Genesis 3 records the episode that began the transformation of their basic nature to the extremes of self-centeredness we witness today. Man's nature was not created evil, but it became evil through the influence of another spirit - besides God - that Adam and Eve chose to follow without any interference from their Creator.
Once they committed to that initial step, the course of this world began. By the second generation, murder had occurred (Genesis 4:8), and by the Flood, men were so evil that they were "only evil continually" (Genesis 6:5). It is this same peak of evil toward which this world and its multiple courses are being driven. All of this takes place because of the communication, reception, and acceptance of evil concepts from an evil source.
II Timothy 3:13 reveals a general principle still working as we "progress" toward the return of Jesus Christ: "But evil men and impostors will grow worse and worse, deceiving and being deceived." Improving character and conduct in any given culture are temporary, indeed very brief, when observed within a survey of all of man's history.
The same process of moral deterioration that concluded with the Flood was quickly restarted shortly after its waters receded, and it persists to this day, as each person is born into this world and exposed to the same spirit and to the variety of courses that influenced Adam and Eve and all their progeny. Because we are made of flesh, we are born with a slight pull toward self, but not with the corruption that later develops and reveals itself in our conduct. Contrary to Catholic Church teaching, evil is not passed on through procreation, but by the spirit of the age through the course of this evil world. It is transferred to us primarily through the cultures into which we are born, all of which are carnal to the core.
It is the responsibility of converted parents to God and to their children to ensure that the right spirit prevails in their homes so their children can be properly nurtured. People grasp this to some degree when they observe that, "The apple doesn't fall very far from the tree," or "Like father, like son." Unless parents make a concerted, persistent effort to change and live as God commands, they will succeed only in passing on copies of themselves.
This world's Christians, in an effort to evade responsibility for the evil in them, have instead blamed God for creating man this way. God is responsible to a degree, in that He has not yet chosen to halt Satan's deceptions. Nevertheless, God did not make us this way. Mankind, represented by Adam and Eve, chose to submit to Satan, and all of their descendants, including us, have also chosen to become evil under the sway of the same evil spirit that offered our first parents the choice. This creates and accounts for "the course of this world."