The length of a biblical generation is not precisely defined in scripture, but there are some clues that can help us estimate the approximate length. Here is an overview of what the Bible reveals about how long a generation typically spans:
Old Testament Insights
In the Old Testament, there are a few verses that give measurements of generations that can help establish a range:
- Genesis 15:16 – The iniquity of the Amorites was not yet complete, so God tells Abraham their judgment would come “in the fourth generation.” This implies a generation was long enough for a society to reach sufficient wickedness to warrant judgment, likely at least 40-50 years.
- Numbers 32:13 – God punished the Exodus generation with wandering 40 years in the wilderness until that generation died off. This associates a biblical generation with the adult life span of those who left Egypt.
- Job 42:16 – Job lived 140 years total and saw his children and his grandchildren, 4 generations in all. This implies about 40 years per generation at that time.
- 2 Kings 8:17-24 – Spans 3 generations from Jehoram to Ahaziah based on father-son relationships lasting about 20-25 years it seems.
- 1 Chronicles 26:31 – The generations of the Kohathites spanned from the time Israel entered the promised land until David’s reign, about 400-500 years covering roughly 10-15 generations.
These measurements suggest a generation in the Old Testament could range anywhere from 40-100 years, but averaging around 50-70 years was common.
New Testament Insights
In the New Testament, Jesus and the apostles also make some references to generations that can give us clues:
- Matthew 1:17 – There were 14 generations from Abraham to David, 14 from David to the exile, and 14 from the exile to Christ. This implies about 40-50 years per generation in Jesus’ genealogy.
- Matthew 24:34 – Jesus tells his disciples “this generation will not pass away until all these things take place” referring to his second coming. If “this generation” means those living at that time, a generation was about 30-40 years.
- Ephesians 3:5 – Paul refers to a previous generation when the gospel mystery was not known. Likely implies a span similar to Old Testament ranges.
From these verses, it seems reasonable to estimate that a generation in the New Testament era was about 40 years, similar to Old Testament figures.
Factors that Determine Generation Length
Why did generations seem to last around 40-50 years on average? There are some cultural and biological factors:
- Having children early – Women married and had children in their teens, allowing 4+ generations to be living concurrently.
- Longer life spans – Many people lived over 100 years, so generations overlapped.
- Language conventions – The term “generation” could refer to different classifications like a lifetime, age cohorts, ancestry, or extended family.
Exceptions and Variations
While 40-50 years was typical, the Bible notes some exceptions too:
- Genesis 11:10-26 – Records 10 generations from Shem to Abraham, indicating 100+ years per generation, perhaps due to longer life spans.
- Exodus 20:5 – God visits iniquity to the 3rd and 4th generation, implying children continued in parents’ sins.
- Matthew 11:16 – Jesus refers to “this generation” to mean the people of his day, not just age cohort.
- Matthew 23:36 – Jesus says judgment will come on “this generation” indicating qualities beyond lifespan.
So biblical generations were typically around 40-50 years, but unusual life spans, ancestry, and sinful influences could lengthen or shorten them. The term also had some flexibility referring more to the characteristics of a group than fixed time periods.
Significance for Today
Understanding how biblical generations span gives us insight when interpreting prophecies and promises:
- Allows us to make reasonable guesses at timeframes like date ranges.
- Helps relate biblical language to modern demographics and timespans.
- Lets us weigh whether arguments based on generations have biblical merit or not.
- Clarifies the limitations of trying to overdefine or calculate exactly when one generation ends and another begins.
Yet while we can estimate approximate lifespans, the emphasis is that God works patiently through generations of families and people groups over the long arc of human history to accomplish His will. Whether 40 years or 100, each generation is called to pass on faith and obey God despite their shifting characteristics and contexts across the centuries.
Old Testament Generation Timespans
Looking closer at some Old Testament accounts gives a sampling of generation lengths in different biblical eras:
Pre-Flood Generations
Genesis 5 lists the genealogy before the flood:
- Adam to Seth: 130 years (Gen 5:3)
- Seth to Enosh: 105 years (Gen 5:6)
- Enosh to Kenan: 90 years (Gen 5:9)
- Average: 100+ years per generation
Lifespans over 900 years caused generation gaps to expand.
Post-Flood Generations
After the flood, generations shortened as ages decreased:
- Shem to Arphaxad – 100 years (Gen 11:10)
- Arphaxad to Shelah – 35 years (Gen 11:12)
- Eber to Peleg – 34 years (Gen 11:16)
- Average: ~40 years per generation
Patriarch Generations
The patriarch’s family tree gives insight into changing lifespans:
- Terah to Abraham – 130 years (Gen 11:32)
- Isaac to Jacob – 60 years (Gen 25:26)
- Jacob to Joseph – 91 years (Gen 41:46, 47:28)
- Average: 60-90 years
Dynasty Generations
The kings show generation lengths as life expectancy stabilized:
- Saul to Ishbosheth – 40 years (2 Sam 2:10)
- David to Solomon – ~25 years (2 Sam 12:24)
- Jehoshaphat to Jehoram – 35 years (2 Kings 8:16-17)
- Average: 35-45 years
New Testament Generation Examples
The New Testament gives a few more patterns to demonstrate the generation concept:
Family Generations
Fathers to sons show similar lengths to Old Testament templates:
- Jesus began ministry at “about 30 years of age” (Luke 3:23)
- Most assume Joseph died before Jesus’ ministry, so approximately 40 years from birth to adulthood.
Historical Generations
From significant events back to Jesus’ day took around 40 years:
- Jesus’ prophecy of the temple destruction to the event in AD 70 (about 40 years)
- Jesus’ resurrection around AD 30 to Peter writing 1 Peter likely around AD 63 (35ish years)
Sequential Generations
Early church fathers lived about one generation in length:
- Peter and Paul born around the same time, ministered about 30 years
- Polycarp was a disciple of John for 40-50 years
So consistent patterns emerge between testaments that affirm the typical 40-50 year generational estimate through multiple lines of biblical evidence.
What Jesus Meant by “This Generation”
When Jesus referred to “this generation” in key verses, did he mean:
- Those alive in that day and age?
- The generation that sees signs fulfilled?
- An ancestry or people group?
- A quality of wickedness?
There are good arguments for each view:
Support for 40 Year Lifespan Meaning
- Many prophecies were fulfilled by 70 AD, within 40 years of Jesus’ ministry, pointing to those alive hearing his words.
- The apostles frequently refer to Jesus’ imminent return in their lifetimes (1 Thess 4:15, 1 Cor 15:51)
Support for Eschatological Meaning
- The signs and events in the Olivet Discourse (Matthew 24-25) point to a future generation witnessing those prophecies fulfilled during the tribulation period.
- Jesus said no one knows the day or hour, so there is a generation alive when He returns but unclear exactly which.
Support for Ethnic Meaning
- Jesus condemned that “generation” and their ancestral sins (Matt 23:36, Luke 11:50).
- Peter references many generations who hoped in Christ (1 Peter 1:12), implying a people group.
Support for Characteristics Meaning
- Jesus rebuked the evil traits of that generation (Matt 12:39, Mark 8:38)
- He contrasts qualities of faithfulness (Luke 20:6)
- So the wicked “generation” could refer to a set of rebellious qualities in people of a certain time and place.
In summary, “this generation” likely combines multiple nuances – timing, ancestry, lifespan, and spiritual conditions. The precise meaning depends on the context of each passage.
How Long Were Jesus’ Generations?
Matthew 1:17 says there were 14 generations:
- From Abraham to David
- From David to the exile in Babylon
- From the exile to Christ
The timespans were approximately:
- Abraham to David: 1000 – 1050 BC to 970 – 931 BC, so about 1000 years
- David to exile: 970 BC to 586 BC, so about 400 years
- Exile to Christ: 586 BC to about 5 BC, so about 600 years
Dividing the timespans by 14 generations gives an average of 40-83 years per generation, but rounding to 40-50 years per generation seems implied. Some factors to note:
- The genealogies likely skip some generations between the major figures for brevity and memorability.
- Lifespans gradually declined closer to modern averages of 25-40 childbearing years.
- The symbolism of 14 generations 3 times suits Matthew’s theme of Jesus’ kingly lineage.
So the evidence fits with the lifetime of a biblical generation being approximately 40-50 years.
Generation Length Reveals God’s Faithfulness
Understanding how long a generation was biblically helps us grasp key themes:
God Works Patiently Through History
Seeing the continuity of families and nations over generations shows God unfolding His plan across ages. He gave promises to Abraham that took hundreds of years to fulfill. Each generation must carry forth faith in God’s faithfulness.
God Outlasts Temporary Generations
“Lord, you have been our dwelling place in all generations. Before the mountains were brought forth, or ever you had formed the earth and the world, from everlasting to everlasting you are God.” (Psalm 90:1-2)
Our lives and eras quickly fade, but God remains forever the same. We can trust Him beyond our brief generation.
Each Generation Must Choose to Follow God
God judged generations in the wilderness due to their unbelief. Jesus condemned hypocrites of his day. We must follow Christ in our generation. No one receives a “free pass” based on ancestry or affiliation.
The spans and meanings of biblical generations give us perspective on walking faithfully with God through the seasons He appoints until He returns.