Bacteria are mostly beneficial, even though a minority are known as pathogens. They are necessary for natural processes such as human digestion and biogeochemical cycling. In a pre-Fall ("very good", Genesis 1:31) world, all bacteria must have been nonpathogenic, and many of the functions they were designed to perform originally can still be seen in a post-Fall world. However, as a result of the Fall, some bacteria now cause disease. Bacteria have pathogenic mechanisms that are very complex and specific (to the host). Genomic islands (GEIs), specifically pathogenicity islands (PAIs), typically harbor the genes necessary for the pathogenic mechanisms of bacteria and are thought to be important determinants of pathogenicity. These islands are gained through horizontal gene transfer (HGT) from other bacteria. Interestingly, comparisons of the genomes of pathogenic and nonpathogenic strains of bacteria have shown that many suspected PAIs reside in both and that PAIs themselves are insufficient for pathogenicity. I propose that bacterial pathogenicity is the result of multiple events in any given bacterium (vs. singular events) that occurred after the Fall and that no intentional pathogenic mechanisms exist. In the post-Fall world, mutations and HGT of GEIs are factors that have resulted in pathogenic bacteria. In addition, the host may have suffered changes (genetic or otherwise) that altered the relationship between itself and the bacteria resulting in pathogenicity. Another factor in pathogenesis may be the exploration of new environments by bacteria that they were not originally designed to interact with. This may be due to changes in the bacteria (HGT of GEIs and mutation) that allow them to explore new niches. It may also be due to host or environmental changes that allow bacteria (with or without genetic alterations) to explore new niches. Displacement and genetic alteration (through mutation and HGT) in the post-Fall world are likely necessary for the adaptation and survival of bacteria but in some cases also have the "side effect" of pathogenicity in living things. Many studies have clearly shown that bacteria have been designed with the remarkable ability to adapt to numerous differing environments. This paper will explore pathogenicity as a post-Fall event in which bacteria have adapted to novel environments due to combinations of mutation, HGT of GEIs, and displacement. A creation model of the origin of bacterial pathogenicity will be developed based on the findings.