The Doctrine of Man and Sin
Who is man and what was God's original design for man? In order to get to the truth, we must not assume anything, especially popular notions of the goodness of man. Let us form our estimation of man from the test of Scripture.
Man Created in Original Righteousness
The Bible teaches man was created in the image, or likeness, of God, setting him apart from all creation (see Gen. 1:26, 1:27, 9:6; Col. 3:10. He was created righteous, not merely neutral. At that point man had a free will and chose to rebel against God (see below about the fall of man). When he sinned he lost his original righteousness and became the enemy of God. Only through Christ can man be restored to God's favor.
Man's Constitution: Body and Soul?
What does man consist of, a body and soul, or a body, soul and spirit? The first view, that man consists of a body and soul, is called the dichotomist view. The second view, man consists of a body, soul and spirit, is called the trichotomist view. Verses that support the trichotomist view include 1 Thess. 5:23:
Now may the God of peace Himself sanctify you entirely; and may your spirit and soul and body be preserved complete, without blame at the coming of our Lord Jesus Christ (NASB).
Another verse cited to support this view is Heb. 4:12. Most supporters of trichotomy would agree that the biblical writers vary their language at times and use adjectives to bring a particular concept. So in Luke 10:27 we're told to love God with all our heart, soul, strength and mind. So then does man consist of a heart, soul and mind? Matt. 22:37 uses similar words but omits "strength." Mark 12:33 enjoins us to love God with our heart, understanding and strength, omitting "soul" completely. We should therefore not conclude that because because various adjectives are used to depict our "soul" or "spirit" they therefore must refer to distinct entities. One good rule of interpretation tells us to answers questions of doctrine, go to the specific verses that speak to that topic.
Gen. 2:7 and Matt. 10:28 speak to the actual constitution of man, namely a body and soul. This seems to indicate man consists of a body and soul, the dichotomist view of man. Besides, the Bible employs the terms "soul" and "spirit" as synonyms (see Luke 1:46-47, where Mary interchanges the terms). We therefore hold to a dichotomist view of man.
The Origin of the Soul
But when, then, did the soul originate, and how did it come into being? The Bible affirms the direct creation of man (cf. Genesis 2), and thereafter the propagation of living beings through normal male/female relations. Plato, and Mormons, hold to the pre-existence of souls, but they have no biblical basis for believing this. That raises the question, "How do souls come into existence?"
Two views have emerged as the leading ones:
- Traducianism
- Creationism
Traducianism teaches that following the creation of Adam and Eve, both body and soul is passed into existence through the normal sexual union of husband and wife. Romans 5:12 is sometimes cited as proof for this view, along with "Genesis 2:2, 21 interpreted by 1 Cor. 11:8" (see Reymond, A New Systematic Theology of the Christian Faith, 424).
Creationism, on the other hand, emphasizes the direct hand of God in creating immediately each soul at conception. Those holding to this view cite Zech. 12:1, Gen. 2:7, Eccl. 12:7, Isaiah 57:16, and Heb. 12:9.
Both of these views have much to commend them and both share some difficulties. Creationists point to some seemingly clear passages in support of their view, whereas Traducianists question how God can create a contaminated soul, and they point to certain character traits transferred from parents to children. Creationists have responded to the first criticism by saying the soul becomes contaminated upon entrance into the world, not precisely at creation (though it appears simultaneous). Good scholars hold to both views, and this matter certainly should not serve as a test of fellowship.
The Fall of Man
When Adam and Eve sinned against God they not only fell away from God's favor, but plunged man into spiritual misery. God, having invested Adam as representative of mankind (sometimes called the "federal representative"), declared Adam guilty and us as well. (See Rom. 5:12-21 for Paul's expanded argument that links our fall with Adam's.) 
They lost their innocence and became thoroughly corrupt in their natures. The image of God within them, while not eradicated, was significantly marred so as to ruin their fellowship with God. Furthermore, God cursed the earth on account of man's sin and it would affect productivity and become subject to vanity (Rom. 8:20-22). Unfortunately, future generations of man would be born alienated from God and liable to eternal misery. Man is now born into this world in a condition of total depravity. We don't like to admit this as our pride repulses against any such notion, but we're condemned and guilty from the womb. Only God's grace in Jesus can set the sinner free.