Theistic evolution sounds similar to Old Earth Creationism. Both ideas start with the premise that God created. After this, I've heard tale of wars fought between the two camps. What is the gist of the differences between these two ideas?
Theistic evolution (TE) is the belief that we should look to the Bible to learn about God, and rely on scientists to inform us about science. As someone once put it, "The Bible tells us how to go to heaven; science tells us how the heavens go. Science can give us the age of rocks; the Bible can give us the Rock of Ages."
This view holds that there is no conflict between faith and science regardless of the conclusions the scientists reach. This viewpoint has been labeled "theistic evolution" because about 98% or 99% of all scientists in the life science fields accept evolution as the best theory to explain the variety of life forms found on our planet.
TE differs from old earth creationism (OEC) in that OEC generally accepts modern geology and cosmology but not evolution.
TE differs from intelligent design (ID) in that ID proponents hold that science can uncover ways in which God is active in the creation process; TE proponents hold that God has been active, but can accept the "how" of God's involvement as a mystery.
Theistic Evolution is the belief that God created life via the evolutionary process as it is understood today by modern science.
There are a few ways in which Evolution might be understood "theistically":
- God might have worked via guided evolution, ensuring that the appropriate mutations and/or environments arose to reach a particular end.
- God might have created the first life, and then "set it loose", with random mutation doing the rest.
- God's work might have simply been to create the world in such a way that life itself would arise (and evolve, adapt, etc.) according to chance and the laws of nature.
I believe that most people who call themselves "Theistic Evolutionists" would go with #3 (Howard Van Till calls this "Fully gifted creation"), although I don't see any reason the term couldn't be applied to those who believe in #1 or #2.
My understanding is that strictly speaking, Old Earth Creationism is the idea of an instant creation, albeit as old as perhaps radiometric dating suggests, whereas Theistic Evolution posits that Evolution did occur (thus all life originated from a single cell, perhaps) and the individual kinds emerged over time, and that this process was either started by, or continually overseen and guided by, God.
To answer the title question, Theistic Evolution is the belief that God guides the evolutionary process, and that this guidance better explains weaknesses in current evolutionary theory.
Theistic Evolution presumes an Old Earth, but Old Earth Creationism does not presume Theistic Evolution, as OEC also allows both for traditional evolution (that God is more of a watch-maker, and did not intervene in the natural selection process after creation) and for no evolution at all (that individual species were created by God at the appropriate times in history) depending on who you talk to.