There are 5 basic categories into which origin models can be divided over a broad spectrum from atheistic evolution to young-earth creationism (see Figure 9.1). Other authors divide origin theories into more categories, but with the increasing number of categories (e.g. "evolutionary Creationists"), there is an increase in the overlap between categories. From my experience, I have found that the following scheme is the most useful. (Note: Examples of individuals may have altered positions since printing.)

1. Atheistic evolution (naturalistic evolutionism):
   The universe and all the physical laws of nature were created by chance during the Big Bang about 15 to 20 billion years ago. We exist through a combination of random processes known as "evolution." There is no purpose or intelligent force which has directed our evolution. We are here only by chance; religion is a natural development in our evolutionary "progress". When we die, we no longer exist.

   Examples: Isaac Asimov, Carl Sagan, Stephen Jay Gould, John Gribbin, Stephen Hawking, Richard Dawkins, Arthur N. Strahler.

2. Deistic evolution:
   A supernatural force created the Big Bang, and set down all the physical laws. This force is no longer involved in the day-to-day operation of the universe. We exist via "evolution", and although a supernatural force may have initiated the process, we are here by chance.

   Examples: Charles Darwin, Albert Einstein, Fred Hoyle, Robert Jastrow*

   *The following is a famous quotation attributed to Robert Jastrow (1978):
   

   "For the scientist who has lived by his faith in the power of reason, the story ends like a bad dream. He has scaled the mountains of ignorance; he is about to conquer the highest peak; as he pulls himself over the final rock, he is greeted by a band of theologians who have been sitting there for centuries." (Jastrow, R. 1978. God and the Astronomers. Reader’s Library, Inc.)

3. Theistic evolution:
   God is the supernatural force who created the Big Bang and set down all the physical laws in order for evolution to occur. He used evolution to "create" the right environment and the right vehicle in which to place a living soul. When the time was right for Adam to appear, God took an evolved pre-man, and gave him a spirit and/or soul to create man in the image of God. This category differs from Deistic evolution by giving evolution a purpose.

   Examples: B.B. Warfield, James Orr, C.I. Scofield, Derick Kidner, Howard Van Till (professor emeritus of Calvin College, and author of The Fourth Day).

4. Old-Earth Creationism:
   This category describes theories that allow for an earth that is older than 6,000 to 10,000 years, and the belief that God created, more-or-less, as described in Genesis 1. In these theories, a particular interpretation of Genesis provides the time needed for fossil formations, and for radioactive dating. There are two subcategories under Old-Earth Creationism which vary depending on how literal Genesis 1 is interpreted. They are: a) The Day/Age Theory; b) The Gap Theory
   
   
   1. The Day/Age Theory: The creation days in Genesis describe creative periods of time, not six literal days. During each creative period, God increased the complexity of life by creating new life forms while changing the earth to accommodate these forms. Variations on the Day/Age theory differ according to how much the appearance of new organisms in the fossil record is attributed to God's direct intervention, or due to the process of microevolution - genetic variation within a species. Some proponents of the Day/Age Theory believe that we are currently in the seventh day (D.A. Young, G. Schroeder). Progressive creationism, a popular theory among Christian academics, is a variation of the Day/Age Theory.

      Examples: Bernard Ramm, Kenneth Taylor, Millard J. Erickson, James Montgomery Boice, Gleason Archer, Hugh Ross (Reasons to Believe), Christianity Today, Davis A. Young, Robert C. Newman, Pattle T. Pun.

   2. The Gap Theory: The belief that an indeterminate period of time exists between Genesis 1:1 and Genesis 1:2, and that the original creation was altered to become "without form and void". The days in Genesis 1 describe God "re-creating" the earth and telling mankind to replenish it. Some proponents of the Gap Theory believe that geological strata were created during the time before the re-creation of the world, and do not believe that Noah's flood was world-wide. This theory was promoted by the founders of modern geology (e.g. T. Chalmers, H. Miller), and is referred to by some as the "ruin-reconstruction" view. This view is found in the Scofield Reference Bible, Dake's Annotated Reference Bible, and the Newberry Reference Bible.

      Examples: Thomas Chalmers; Hugh Miller; G.H. Pember (Earth's Earliest Ages, 1884); Arthur Custance (Without Form and Void, 1970).

5. Young-Earth Creationism (Scientific creationism, Creation Science):
   God created all matter in 6, 24 hour days, about 6,000 to 10,000 years ago. This theory disagrees with dating methods that show the earth to be older than 10,000 years, but it agrees with a literal translation of the creation week in Genesis 1.

   Examples: Henry H. Morris, Duane T. Gish and those associated with the Institute for Creation Research and the Creation Research Society; Ken Ham (Answers in Genesis); John Mackay (Creation Research, Australia).