Very simply and in a straightforward way, God states the purpose for which He created the garden, and begins to reveal foundational parts of the training program for Adam and Eve. Spiritually, this principle extends to His modern children as well.
Adam's job in the Garden was to "tend and keep" or "cultivate and guard." A deeper study of the words show that in combination, tending or cultivating is a form of keeping. Cultivation is the effort a farmer makes to ensure that he will produce as bountiful a crop as possible. He plows the ground, fertilizes it, plants the seed, then he promotes further growth by watering, weeding, and so forth. If the farmer is lazy, if he fails to cultivate his ground, if he does nothing to promote growth, then what occurs? Nature follows its course and the farm begins to degenerate!
This law can be illustrated by somewhat different examples. Suppose you own a new house, complete with a fresh coat of paint on the exterior. If nothing is ever done to maintain the house in good condition, the house will degenerate very quickly. The same applies to an automobile. If you never change the oil, never lubricate it, never inflate the tires to the right pressure, never wash it, degeneracy results. It is part of the law of the universe. If a thing is not maintained, if nothing is done to guard against decay, degeneration will surely occur. If nothing is done to cultivate, nature will take its course, producing degeneration.
In very simple terminology, God's purpose is accomplished because men and women cultivate and guard. They cultivate what is provided to them in terms of both physical and spiritual things. If cultivation occurs, it will guard against degeneration. So another principle begins to emerge: Not only must sound training come from pure doctrine, but we must make an effort to cultivate, producing more fruit and greater growth. If we neglect this great salvation, our spiritual lives are going to degenerate. The truths that we formerly held in high esteem will begin to slip away.
At the very beginning of the book, God warns of a natural tendency in everything toward disintegration.