The term biogenesis refers to the production of life from already-living matter or organisms. This is in contrast to abiogenesis, which refers to the production of life from non-living matter. Natural abiogenesis has never been observed, nor are there any generally accepted models for how it could occur. Biogenesis, on the other hand, is routinely observed at all levels of life. When a bacteria divides, a plant produces seeds, or a mammal gives birth, biogenesis is occurring.
Biogenesis is also different from creation ex nihilo, which refers to God’s forming something supernaturally out of nothing (Genesis 1:1). In biogenesis, living creatures form more of their own kind, with possible slight variations, through a natural process. In creation ex nihilo, God produces something that never existed in any form or in any components. Biogenesis is also a separate concept from creation ex materia, where God forms existing materials into something completely different. When God created Adam out of dust (Genesis 2:7), this was an example of life arising through an ex materia process.
Despite how obvious biogenesis may seem now, it was only accepted by the scientific community at large about 150 years ago. Ancient cultures believed that inanimate materials such as straw and meat would transform into mice and flies, respectively. Later, it was believed that this kind of spontaneous generation only occurred in simpler organisms such as bacteria. It wasn’t until Louis Pasteur experimentally proved spontaneous generation false, in the 1860s, that the scientific community fully accepted biogenesis as the only natural source of living things.