How old is planet Earth? Why does it matter? Various branches of science agree, based on substantial evidence, that our planet is about 4.5 billion years old. Many Christians argue that it is only a few thousand years old, and they make it a matter of faith. In other words, if you disagree with their timeline, you are an evolutionist and Bible denier. Scientists have methods for calculating Earth’s age, and they have nothing to do with faith or denying the Bible. The truth is that Earth’s age is irrelevant to Christian faith.
Why do many Christians insist on a “young” Earth? It may be because they believe the Bible says so. They base that on a document written by an archbishop of the Church of Ireland, James Ussher, published in 1654. He calculated that Earth’s creation took place on October 22, 4004 B.C. He based his calculations on the assumption that the genealogies of Genesis are complete and that they are recorded for the purpose of chronology. Those assumptions are not correct. The biblical genealogies are incomplete, and their purpose is to show lineage, not chronology. Of course, the lineage eventually led to the Messiah. Because early English translations of the Bible included Ussher’s chronology, many came to believe it was the gospel truth.
Another significant reason many Christians today choose to believe in the young-earth doctrine is that they think it refutes evolution. Scientists don’t insist on billions of years to allow time for evolution. A little-known fact that scientists are reluctant to admit is that 4.5 billion years is not long enough for unguided evolution to create the diversity of life on Earth today. In reality, no amount of time is sufficient for random mutations and natural selection to accomplish the task. But not all of the 4.5 billion years are available for evolution. A large amount of time would be required for the planet to cool and become suitable for life. Then, more time would be needed for non-living elements to organize themselves into the first living cells. (They couldn’t do it by themselves in any amount of time, but that’s another issue.)
The bottom line is that Earth’s age is irrelevant to Christian faith. The age of the Earth is essential to the sciences of geology, paleontology, astronomy, physics, chemistry, and others. As it relates to the Christian faith and the accuracy of the Bible, Earth’s age is irrelevant and always will be. Archbishop Ussher was an intelligent church leader and scholar, but his chronology fails because he based it on false assumptions. False assumptions lead to false conclusions.
— Roland Earnst © 2025