Old Earth creationism (OEC) is a form of creationism that accepts the existence of deep time, and may accept scientific evidence about the age of the Earth. As with all forms of creationism, it maintains that the earth and the universe were created by a god, usually the Abrahamic God (Christianity, Judaism and Islam).
OECs reinterpret biblical descriptions of the two differing creation stories in the book of Genesis in order to fit real-world facts about the age of the Earth, cosmology and — in some forms — even the facts of evolution. As a result, OEC requires adherents to disregard considerably less evidence than its young-Earth cousin.
 Main divisions
Old Earth Creationism is harder to define than Young Earth Creationism as believers vary in how far they go in accepting full biblical literalism on the one hand and empirical reality on the other. Nevertheless, the concept can be divided into a few general classes. It is clear that, although some of the ideas are mutually exclusive, it is possible to mix and match others depending on the believer's grasp of reality.
The answersincreation website carried out a (likely unscientific) poll of Old Earth Creationists which indicated that "45 percent are Progressive Creationists, 32 percent are Theistic Evolutionists, 10 percent believe in the Gap Theory, and the rest are old earth, but undecided as to which position to believe in".
 Day-age creationism
 Progressive creationism
The main thrust of progressive creationism is that there were a series of individual biological creation events and consequently the concept is incompatible with common descent. There are a number of subdivisions and various combinations are possible.
- In all versions of progressive creationism the days of creation are assumed to be much longer than 24 hours. In some versions each day is assumed to be a fixed thousand years. In others, millions (or billions) of years may be assumed to pass and each "day" may not represent the same fixed period of time.
- In some versions the days are entirely separate periods; in others the days may overlap with each other.
- In some versions the chronological one of the two sequences of events as stated in Genesis is held to be true, while others hold more flexible interpretations of the chronology.
Typically, although Progressive Creationists believe in an old earth, they are unable to bring themselves to accept the evidence for evolution by natural selection. Instead they believe that each species was the subject of a separate individual creation event — without evolving from a previous species. In order to do this they have to ignore the incontrovertible evidence of common descent.
 Theistic evolution
- either let evolution run its natural course via natural selection (in which case it's not clear what is "theistic" about "theistic evolution"; indeed it might be better described as "deistic evolution")
- guided evolution to produce humans. (The method of such guidance is not specified, although some adherents claim it could be the pseudoscience of Intelligent design for which no credible evidence has ever been presented.) Another term sometimes used is scientific creationism.
 Gap Creationism
 Supernatural processes
Those who advocate the Gap theory or progressive creationism claim that God did not just perform a single act of creation but many (even as many as millions) over long periods of geological time, each time creating new species or higher taxonomic groupings. During the intervals when God was not creating, microevolution was taking place, to allow minor adaptations within species. The progressive creationist Alan Hayward (1923–2008) proposed the process of "successive creation" that “God has been at work ever since the universe began, performing a great number of creative acts at intervals”.
The Gap theorist Arthur Custance (1910–1985) proposed the hypothesis of supernatural selection as a process for how new species originate. Both "successive creation" and "supernatural selection" are supposed to be supernatural replacements for known natural evolutionary processes. The problem with the supernatural processes of Custance and Hayward is that they are not testable and are really no different than just saying God did it.
 Intelligent design
The more scientifically minded believers in intelligent design take on board all ideas about the age of the earth and even common descent, but maintain that evolution is controlled and managed by "somebody". The less scientifically minded include—well—less science. There is zero real evidence in support of any of the ID variants.
 Noah's Flood
Beliefs in a biblical flood tend to vary amongst OECs. While some — perhaps especially those who hold to the "Gap Theory" — may maintain that a full global flood occurred, others scoff at the idea and point out its many failings. They prefer to believe in a smaller localized event (or events) and claim this inspired the various flood stories around the world. Yet others will prefer the pseudoscience of Hydroplate theory.
 See also
- Young earth creationism
- Expelled: Leader's Guide
- Evidence against a recent creation
- Revelation Theory of Creation
- Alan Hayward