One of several, actually
Even a casual reading of the Ten Commandments (either Exodus 20 or Deuteronomy 5) should make anyone skeptical that a supposedly good, competent god had anything to do with it. Here was this god’s big opportunity—alone with Moses on the mountaintop—to let humanity know the best moral principles to follow. Many ethicists have noticed three crucial items that are missing: (1) Thou shalt not engage in warfare; (2) Thou shalt not enslave other human beings; (3) Thou shalt not mistreat or undervalue other human beings because of the color of their skin. These omissions are surely an indication of defective, indeed bad theology.
Slavery and racism have brought so much pain and suffering to the world. But war has been, by far, the greatest destroyer, especially as weapons have become more and more advanced—very smart people have been hired by military leaders to create devastating killing machines. This prompts us to doubt, on another level entirely, that a good god was involved in the creation of humans.
Debunking Christianity