For two billion Christians across the globe, the Bible is a highly credible reference that reveals important truths about life and God. Because it is a religious text riddled with the beliefs of an ancient civilization, though, it is not a reliable source on some matters, such as scientific debates. The Bible's validity as a source depends on how and why you are using it.
It's always acceptable to cite the Bible when you need to quote biblical history or gain insight into Christian beliefs. However, the Bible isn't always the final word. If you cite the Bible as a literal source of Christian beliefs without adding another source, you could mislead your readers. For example, not all Christians believe humans can or did live for hundreds of years, or that God created the world in seven days.
If you rely on the Bible as a source for political information about biblical times, you also should draw from other sources as well, since the Bible has a subjective viewpoint. You can, however, note how a historical event was perceived by characters in the Bible, and may be able to use the Bible as a starting point for further research on issues such as Roman occupation, Hebrew political history and historical figures in the Bible.
Philosophical and Ethical Information
The Bible is an ideal source for a paper on ethical philosophy, but should represent only one source of information on one type of philosophy, not the final word. Additionally, if you rely on the Bible to gain insight into the beliefs of early Christians or ancient Jews, it's usually a good idea to cite a second source as well, since not all people of the time believed the philosophies discussed in the Bible.
The Bible is not a scientific document, and the contents of the Bible are often metaphorical, rather than literal. Consequently, the Bible is not a reliable source for information on evolution, cosmology, medicine and similar scientific issues. It also can't provide up-to-date information on political geography, human psychology and other modern fields.