What Scripture says
The law of Moses includes instructions that fit modern health principles:
- Isolation: a person with a contagious skin disease “shall live alone. His dwelling shall be outside the camp” (Leviticus 13:46, ESV), and suspected cases were isolated for seven days and re-examined (13:4–5).
- Washing: people who touched bodily discharges or dead bodies had to wash themselves and their clothes (Leviticus 15, Numbers 19:11–19).
- Sanitation: human waste was to be buried outside the camp (Deuteronomy 23:12–13).
- Contaminated objects: clothes and pots touched by dead animals were washed or broken (Leviticus 11:32–33).
What the evidence says
Context
What fits well
The quarantine and washing laws are genuinely striking. In the 19th century, the Hungarian doctor Ignaz Semmelweis showed that doctors who washed their hands after handling corpses dramatically reduced deaths among mothers in childbirth. His colleagues resisted the idea. Leviticus and Numbers had required washing after contact with the dead thousands of years earlier, though for reasons of ritual purity rather than germs.
Popular claims that are overstated
| Claim | Problem |
|---|---|
| Job 26:7 (“hangs the earth on nothing”) proves the Bible knew about gravity and space | Poetic description of God’s power, not a scientific statement |
| Isaiah 40:22 (“circle of the earth”) proves a spherical earth | The Hebrew word likely means a flat disc or the horizon (see 2.1) |
| Leviticus 17:11 (“the life is in the blood”) anticipated modern medicine | Blood’s importance to life was obvious to ancient people |
| Psalm 8:8 (“paths of the seas”) inspired the discovery of ocean currents | Matthew Maury’s story is popular but uncertain, and the verse is poetic |
| Circumcision on the eighth day matches peak blood-clotting factors | Based on a misread study; clotting factors don’t peak on day eight |
| Genesis 1 matches the Big Bang order | Some parallels exist, but Genesis 1 isn’t written as cosmology (see 1.2, 2.5) |
Why it matters
The Bible wasn’t written as a science textbook. It uses ordinary language about the world, describing things as they appear (see 2.2). Claims that read modern science into ancient poetry often misread the text, and when they’re exposed, they damage the Bible’s credibility rather than strengthen it. Augustine warned about this in the 5th century: Christians who talk nonsense about the natural world bring Scripture into disrepute (The Literal Meaning of Genesis 1.19).
Science
Purity, not germ theory
The purity laws were about holiness and separation from death and decay, symbolizing that God is life (Leviticus 11:44–45). Some had health benefits, but others, such as food laws, had less obvious health logic, and Jesus later declared all foods clean (Mark 7:19; see 8.5). Ancient Israel had no germ theory. The laws reflect wisdom that, in God’s providence, also protected health.
Where they meet
A few points fit well, like quarantine and washing laws (Leviticus 13–15). Many popular claims are overstated; the Bible isn’t a science textbook, and stretched claims hurt credibility.
What’s still open
How to understand the purpose of laws that also had health benefits.
Bottom line
A few points fit well, like quarantine and washing laws (Leviticus 13–15). Many popular claims are overstated; it isn’t a science textbook, and stretched claims hurt credibility. This is rated Debated.