Viruses get a bad rap. Typically, we only think about all the harm they bring. The COVID-19 pandemic is one recent example. It brought worldwide terror and great economic harm. COVID joins a long list of deadly viruses that makes many of us wish viruses never existed. Viruses also bring existential angst. Why would an all-powerful, all-loving God create a world with viruses?

Known Benefits of Viruses
Essential for complex life. Life-forms on Earth larger and more complex than microbes would be impossible without abundant diverse viruses. If not for these viruses, bacteria would multiply and quickly occupy every niche and cranny on Earth’s surface. Earth would become a giant bacterial slime ball. Those sextillions of bacteria would consume all the resources essential for life. All life, including all the bacteria, would die.

Bacterial population check. Viruses kill and break apart bacteria at just-right rates in just-right locations to maintain a population and diversity of bacteria that is optimal for both the bacteria and for all other life-forms. We wouldn’t be here without viruses!

Water cycle. All terrestrial life crucially depends on the water cycle. All the water cycle’s precipitation components (rain, mist, snow, hail, and sleet) require microscopic seeds (or nuclei) to form. The most important seeds for precipitation are viruses and bacterial fragments resulting from viral attacks. While dust and soot particles can also serve as seeds for the formation of raindrops and snowflakes, viruses and bacterial fragments allow the initial ice crystals to form at warmer temperatures. We would not have sufficient precipitation over a sufficiently broad area to sustain our agriculture and civilization if not for viruses.

Medical applications. Viruses are beginning to play major roles in medical therapies and in advancing medical technology. Humans now possess the technology to reengineer natural viruses to combat cancer and cure genetic diseases.

Viruses as Drivers of Biogeochemical Cycles
Another benefit of viruses is the crucial role they play in Earth’s deep carbon, oxygen, and water cycles. As I have explained in my new book, Designed to the Core, each of these three cycles must be amazingly fine-tuned for global human civilization to be possible.1 Viruses play a major role in this fine-tuning.

Viruses and the bacterial fragments they create are carbonaceous substances. Through their role in precipitation, they form vast carbonaceous sheets on ocean surfaces. These carbonaceous sheets sink slowly and eventually land on the ocean floors. As they sink, they provide important nutrients for deep-sea and benthic (bottom-dwelling) life. Plate tectonics drives much of the viral and bacterial fragments into Earth’s crust and mantle where some of that carbonaceous material is returned to the atmosphere through volcanic eruptions.

Viruses ensure that carbon, oxygen, and water are cycled from the atmosphere and oceans into Earth’s crust and mantle with just-right amounts returned to Earth’s oceans and atmosphere. Previous studies revealed that the population level of DNA viruses in the world’s oceans is far greater than the populations of all species of marine life combined.2 There are an estimated 1030 DNA viruses in the oceans. If stretched end to end these viruses would extend all the way to the supergiant galaxy NGC 5128, 10 million light-years away. Every second, about a hundred billion trillion DNA viral infections occur in the oceans, killing about 20% of marine microbes daily.

Thanks to the Tara Oceans Expeditions (TOEs), ecologists are now gaining an accurate picture of the population, diversity, and ecological and geochemical roles of marine RNA viruses. The TOEs doubled the number of known viral phyla from 5 to 10.3 They identified 44,779 different RNA virus contigs (distinct sequences of DNA or RNA fragments).

A recently published analysis of the TOEs data established the following:4
1) The abundance and diversity of RNA viruses are comparable to that of DNA viruses.
2) DNA and RNA viruses infect different hosts.
3) DNA viruses predominantly infect prokaryote microbes while RNA viruses predominantly infect eukaryote microbes.
4) RNA viruses have shorter and faster-evolving genomes than do DNA viruses.

Optimal Fine-Tuning Shows Design
The team that performed the analysis of the TOEs data concluded that the abundance and diversity levels of both DNA and RNA viruses must be fine-tuned in all six marine ecological zones (Arctic, Antarctic, Temperate Epipelagic, Tropical Epipelagic, Temperate Mesopelagic, and Tropical Mesopelagic) to maintain optimal marine ecosystems. Similarly, the abundances and diversities of both DNA and RNA viruses must be fine-tuned to maintain the deep carbon, oxygen, and water cycles at levels optimal for advanced life.

This research shows that the more we learn about viruses the more evidence we uncover for God’s supernatural design and care of all Earth’s resources. That care extends to all Earth’s species of life and especially to the human race.

Check out more from Reasons to Believe


  1. Hugh Ross, Designed to the Core (Covina, CA: RTB Press, 2022), 211–218,
  2. Curtis A. Suttle, “Marine Viruses—Major Players in the Global Ecosystem,” Nature Reviews Microbiology 5, no. 10 (October 2007): 801–812, doi:10.1038/nrmicro1750.
  3. Ahmed A. Zayed et al., “Cryptic and Abundant Marine Viruses at the Evolutionary Origins of Earth’s RNA Virome,” Science 376, no. 6589 (April 7, 2022): 156–162, doi:10.1126/science.abm5847.
  4. Guillermo Dominguez-Huerta et al., “Diversity and Ecological Footprint of Global Ocean RNA Viruses,” Science 376, no. 6598 (June 9, 2022): 1202–1208, doi:10.1126/science.abn6358.

About The Author

Dr. Hugh Ross

Reasons to Believe emerged from my passion to research, develop, and proclaim the most powerful new reasons to believe in Christ as Creator, Lord, and Savior and to use those new reasons to reach people for Christ. I also am eager to equip Christians to engage, rather than withdraw from or attack, educated non-Christians. One of the approaches I’ve developed, with the help of my RTB colleagues, is a biblical creation model that is testable, falsifiable, and predictive. I enjoy constructively integrating all 66 books of the Bible with all the science disciplines as a way to discover and apply deeper truths. 1 Peter 3:15–16 sets my ministry goal, "Always be prepared to give an answer to everyone who asks you to give the reason for the hope that you have. But do this with gentleness and respect, keeping a clear conscience." Hugh Ross launched his career at age seven when he went to the library to find out why stars are hot. Physics and astronomy captured his curiosity and never let go. At age seventeen he became the youngest person ever to serve as director of observations for Vancouver's Royal Astronomical Society. With the help of a provincial scholarship and a National Research Council (NRC) of Canada fellowship, he completed his undergraduate degree in physics (University of British Columbia) and graduate degrees in astronomy (University of Toronto). The NRC also sent him to the United States for postdoctoral studies. At Caltech he researched quasi-stellar objects, or "quasars," some of the most distant and ancient objects in the universe. Not all of Hugh's discoveries involved astrophysics. Prompted by curiosity, he studied the world’s religions and "holy books" and found only one book that proved scientifically and historically accurate: the Bible. Hugh started at religious "ground zero" and through scientific and historical reality-testing became convinced that the Bible is truly the Word of God! When he went on to describe for others his journey to faith in Jesus Christ, he was surprised to discover how many people believed or disbelieved without checking the evidence. Hugh's unshakable confidence that God's revelations in Scripture and nature do not, will not, and cannot contradict became his unique message. Wholeheartedly encouraged by family and friends, communicating that message as broadly and clearly as possible became his mission. Thus, in 1986, he founded science-faith think tank Reasons to Believe (RTB). He and his colleagues at RTB keep tabs on the frontiers of research to share with scientists and nonscientists alike the thrilling news of what's being discovered and how it connects with biblical theology. In this realm, he has written many books, including: The Fingerprint of God, The Creator and the Cosmos, Beyond the Cosmos, A Matter of Days, Creation as Science, Why the Universe Is the Way It Is, and More Than a Theory. Between writing books and articles, recording podcasts, and taking interviews, Hugh travels the world challenging students and faculty, churches and professional groups, to consider what they believe and why. He presents a persuasive case for Christianity without applying pressure. Because he treats people's questions and comments with respect, he is in great demand as a speaker and as a talk-radio and television guest. Having grown up amid the splendor of Canada's mountains, wildlife, and waterways, Hugh loves the outdoors. Hiking, trail running, and photography are among his favorite recreational pursuits - in addition to stargazing. Hugh lives in Southern California with his wife, Kathy, and two sons.

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