For the Greeks, the source of goodness is spirit, and evil has its roots in matter. Because a human being is composed of both matter and spirit, a struggle is constantly going on within one's own nature. The conflict between good and evil that takes place in the life of an individual is a conflict between the desires of the flesh and the demands of the reason, which is the ruling part of one's spiritual nature. The Greek idea of a good mind and an evil body was never accepted by Jews, who teach that man is created in the image of God. Body, soul, and spirit constitute a unit that is good. Evil entered the world with the Fall of man and infected all of the elements in his nature, including his mind and his body. The apostle Paul was brought up in the Jewish tradition, and nothing indicates that he ever abandoned the notion of original sin. Nevertheless, in writing to Gentile Christians, he frequently uses the language of Greek philosophy. For example, in the Epistle to the Galatians, he writes, "So I say, live by the Spirit, and you will not gratify the desires of the sinful nature. For the sinful nature desires what is contrary to the Spirit, and the Spirit what is contrary to the sinful nature. They are in conflict with each other. . . . But the fruit of the Spirit is love, joy, peace, patience, kindness, goodness, faithfulness, gentleness, and self-control."
The Greek conception of a good mind but an evil body is illustrated also in the teaching concerning the immortality of the soul. Unlike the Hebrews, who never accepted the idea of a soul existing apart from the body, Plato and many of his followers believed that souls have neither a beginning nor an end. They belong to the eternal realm of the spirit but are capable of entering human bodies and remaining there until the body dies. During this time, they can be influenced by their contact with that which is physical. As a result, they may be dragged down toward the level of matter or may so direct the physical body that its activities will be in the direction of spiritual attainments. In one of Plato's well-known dialogues, the soul is described as being something like that of a charioteer who is driving two steeds, one of which is wild and unruly, the other of which behaves in an orderly manner. The charioteer determines which one of these steeds will be subdued by the other. The two steeds represent the flesh and the spirit, and the charioteer is the soul. The soul, throughout the course of its embodied existence, is engaged in a conflict between flesh and spirit, which is also a conflict between evil and good. Souls that yield to the demands of the flesh are deserving of a different fate than those that follow the prompting of the spirit. This belief is one of the main reasons why Plato believed in the immortality of the soul. Souls that do not receive the happiness that they deserve in one life can be given a just compensation in another one. This argument provides a solution for the problem concerning the suffering of comparatively innocent persons: They may be receiving just punishment for deeds done in a former existence, or they may be given an appropriate reward in a future one.
